My Sim thinks she's in her first trimester of pregnancy when she's not pregnant at all...

Try deleting the localthumbcache file and see if that does anything. I think info about mods are stored there, which is why you're supposed to delete it when you take out or delete mods from your mods folder. Idk if that will work though, worth a try. Otherwise I know that mc command center has an option to terminate pregnancies, you could install it temporarily if you don't have it and try do that. Or repair your game.. Idk.