could I be pregnant?

I just had my period the 7 ( spotted really light ) and then the 8- 12 ( somewhat of the 13 ). then had some light brown discharge on the 14. I was just wondering if I could be pregnant if I had a full period clotting and all and had enough to fill 2-3 tampons a day. i’ve been on birth control but in december I took antibiotics which basically makes the birth control not work, and I was just wondering what my chances of with getting pregnant and if I could be. I took a test 2 days before my period and the day of the 8 I took one where my period was actually bad and it came back negative. my boyfriend and I had unprotected sex the 31 of december and the 1 of January and was just wondering if I had a period like that if I could be. i’m 20 years old and feel really stupid for asking but he’s the first guy i’ve been with and i’m new to the whole sex thing. & yes I know I was stupid for having unprotected sex without being on my pill but we routinely did it when I was on the pill. any information is needed.