I let a guy place the head of his penis inside my vagina only about an inch. He said he didn't pre-cum and it was only for a few seconds but I forgot to take my pill that day and I started my period the next morning. This was 4 months ago. I took a pregnancy test and it said I was not pregnant. But I think I might have pee'd on it too much. Is that possible? Lately i've gained 5 pounds i've had a normal period every month and took my birth control correct now. But i've been having a few symptoms of pregnancy, including gas, sensitive smell, and um tiredness. Do you think I could be pregnant? Or would I already know for sure after 4 months.