This fic is canon, to an extent. I went back and changed a few things from the actual show to set up my story:
Quinn Fabray called the Schuester residence the Tuesday before sectionals. Under pretense of packing up her crafting supplies for the 'nursery', Terri was in the second bedroom at her crafting table when the phone rang, and rose to answer, absently adjusting her pregnancy pad as she did so:
"…Mrs. Schuester?" there was a pause as the question hung for a moment over the line before the voice continued hesitantly, "…It's Quinn. Quinn Fabray."
"Oh, Quinn!" Terri's voice brightened considerably and although her husband was working late overseeing Tuesday detention, she glanced habitually over her shoulder before lowering her voice conspiratorially. "How's everything going?" she asked quickly, "With the baby? You're not calling to ask for money again? Because you're thin dear, you can make it work-"
"…This isn't about maternity clothes, Mrs. Schuester," Quinn's voice was soft on the line, and hesitant. This made Terri pause. There was a brief silence.
"What about a new ultrasound DVD?" she demanded bossily, "I'm due for another appointment soon and my husband will be wanting to see his daughter-"
Quinn was quiet on her end.
"Mrs. Schuester…" she started finally, "…I called because I need to tell you something…"
Terri's brow furrowed into a tense frown and she sat down in her crafting chair and waited, placing a distracted hand on her belly.
"What is it?" she question finally, when Quinn didn't speak.
"I…" Quinn hesitated, and although Mr. Schuester's wife could not see this over the phone, her eyes were bright as she continued, "I…I'm keeping my baby, Mrs. Schuester. I want to keep her."
Terry Schuester called her sister Kendra in near hysterics.
"It's over, Kendra!" Her usually high voice was so shrill, Kendra had to move to another room to hear her above the yells of her children. She smacked her gum, frowning.
"What's over?" she demanded, not following.
"The baby!" Terri practically shrieked, "Will! My marriage! Kendra, Quinn Fabray is keeping her baby!"
"What?" Kendra locked the handle of her bedroom door to keep her screaming children on the other side. They pounded against it and she turned her back, her mind whirring into fix-it mode. "Terri, what happened? I thought the babysitting-"
"It did!" Terri cut her sister off, "It did work. Or, it didn't, not really, but then it did! But now she's saying she's keeping it, and she won't change her mind! Kendra, it's over!" Terri moaned dramatically. Will, he'll hate me!'
"Calm down!" Kendra snapped, pushing her gum to the other side of her mouth and smacking even harder, "This was all getting too complicated, anyways-"
"What am I supposed to do now?" Terri beseeched shrilly, "Kendra, I have to tell him!"
"No!" Kendra objected fiercely, "No, Terri, you can't do that. He'll leave you and your marriage will be over-"
Terri gave a distressed moan and Kendra continued quickly, speaking over her:
"You faked a pregnancy, right?"
Terri nodded, an action Kendra could not see over the phone. She continued none the less:
"Well then," she decided, her mind already jumping head with possibilities, "You can fake a miscarriage."
"…I don't want to hurt him," Terri spoke in a small voice. "Oh…" she moaned dramatically, "I can't do this! I can't!"
"Shut-it Terri!" Kendra demanded bossily, 'It's too late for that! Don't you think he would have figured it out when you wouldn't let him touch you for nine months? If he never got to feel the baby kick? This was all getting too complicated, a miscarriage fixes everything!"
"Don't you see?" Kendra objected forcefully, excited at the new leg of their plan, "This buys you time, Terri! You miscarry Will's daughter and he'll be forced to care about you! You'll be going through something together! And then, after a few months, you get pregnant for real- no unreliable teenagers. No Quinn Fabray. Will never has to know-"
"How?" Terri interrupted, hesitant. "I don't want to hurt him. Will wants this baby-"
"What baby?" Kendra demanded, annoyed. "You don't have a baby, you hysterical dummy! You fake a miscarriage. You tell Will how much you wanted to have a family with him…you slowly overcome this together-"
"I don't want to hurt him," Terri said, for a third time, looking down to trail her hand over her fake-pregnant stomach.
"It's too late for that, Terri," Kendra spoke truthfully.
Terri looked up at the clock on the wall. Will would be home soon. She mentally ran through her options a final time. Kendra was right…She turned back to the conversation with a determined look.
"When?" she demanded softly.
…It was all getting too complicated, anyways.