What is this?

So last month my boyfriend and I thought I was pregnant because we had sex twice but in between the first and second time he didn't pee. I was having headaches and fatigue and some back pain and my period was late by a few days and then it came but it was lighter than normal. I took two tests and they were negative. Well I'm still having the headache and fatigue and back pain but now I'm having some nausea in the morning and I'm late yet again for  my period. I was supposed to start yesterday. I wiped just now and this showed up. What does it mean?