is there a chance?

i think it might just be all in my head, but i’m on birth control pills and i’m awful at taking them, i also skip days. i’ve gotten my period on the 19th of both march and february but it’s april 23rd now and still nothing, i started my new birth control pack after skipping some days while having unprotected sex. i’ve been having some cramping that started just today, and last couple days i’ve been nauseous and my boobs hurt so bad, plus in the afternoon of the last 4-5 days i’ve gotten the feeling of carsickness while not even being in a car. do i just have a stomach bug and all in my head? or should i worry about being pregnant?