Don't know why!? TMI PIC!

Ok so I have irregular periods due to my weight. I was put on provera for a year almost and haven't conceived. I stopped it in December of 2014. In the last month i lost 15 lbs and finally started my period on my own on February 25th that lasted til March 3-4. Me and hubby BD'd on March 6th. I have been taking Evening Primrose oil for last 5 days to help with cervical mucus. Then today around 7 pm I had a sharp pain in my left pelvic area so I went to the bathroom a minute later and when I wiped I got this. It has not happened since. Im on CD 14. Any opinions on what it could be? All Walmart brand ovulation tests have shown negative for last 5 days. All have faint lines though. I take them in evening but don't stop fluid intake for any amount of time before I take them. Thx for your time!