Help! TMI warning

So on February 21st my boyfriend and I had unprotected sex and he had came inside of me. Since then I've had these mild/slightly severe headaches that last all day, and within the past day or two I've also noticed some cramping. Very early this morning I work up and had to rush to the restroom and had diarrhea (tmi, I know, I'm sorry) and while sitting there I felt very dizzy and queasy. I also noticed some watery bleeding and collected some on the tampon in the picture but my period is supposed to start until 3/3. My cycles have been off ever since I got off birth control last summer and have consistently been 45 days apart since October and I've never experienced spotting before my period. Am I looking too far into these symptoms that are likely just PMS or should I be concerned that I am pregnant? Help please! And again, I apologize for going so into detail but I'm a bit concerned. Any help and personal experiences that are similar to my own are appreciated.