Help please!

I had my last period around December 24th, didn’t have it at all during January, and now it’s February. My s/o and I have had sex a couple of times but he always wears a condom. I’m not on bc. Was wondering if this could be because of a weight gain due to the amount of food I’m eating again since I’m off of school break (I lose weight whenever there’s a break from school) and stress due to school and work or if I somehow got pregnant. I wasn’t planning on it since I’m only 19 and my parents would probably kill me (especially since they don’t know I’m seeing someone). This is the first guy I’ve ever been with too 😬