Premature birth and birth control

I went into labor at 22 weeks and gave birth to a my baby, he lived about 4 hours. I went on birth control at 6 weeks postpartum, and it's been just over a week. I never got my period back before going on bc. The last few days I've had pregnancy symptoms I had the first time. But I'm unsure on when to take a test since I haven't had a period in so long. I don't want to change my lifestyle just in case and then not be pregnant, too painful.