I have been having unprotected sex since may. my period comes like clockwork every month on the 26th but the last one was different. I was feeling sick had sore breasts and nipples  I took a test but it was negative then a day later I started bleeding that was June 23rd. 3 days early which never happens. it was just light spotting and then I got a medium flow that was reddish brown and then got lighter but only lasted 3-4 days which isnt normal for me. usually my periods are extremely heavy and last 7-10 days but this one was different. On Tuesday July 6th I started spotting very little and then it stopped, Ive also been nausea and getting headaches. I took a test but it was negative again, I currently have a UTI and wondered if it is affectig my pregnancy test or could it be too early to tell? If I am pregnant I would only be about 4 weeks along… any advice?