Can I trust a negative pregnancy test 4 weeks after genital contact with my boyfriend? I have take two tests, and both were negative. I am also on the pill, and only took it late by 12 hours one time. I got a withdrawal bleed, but it was a little lighter than normal. My doctor said that it could be a side effect of the pill. I have been feeling bloated and a little nausea lately, but also just got diagnosed with a UTI. Can I trust this negative pregnancy test?