TWW Symptoms

Newbie here so here's a little insight first. I'm 19, my husband is 30 and we just married April 15th of this year. We have been actively TTC since around the beginning of May. Now onto my question - AF just left Friday June 9th, and lasted longer than normal. I am also having a couple of other weird symptoms. I took one HPT Saturday night and it was a clear negative. Wondering if I could have conceived one of the nights leading up to AF and now experiencing implantation? Which would explain the negative HPT but still having pregnancy symptoms.. I have read that it's possible in women with irregular cycles, and I do have somewhat off cycles, ovarian cysts (some hemmorhagic), and PID. Just curious as to if any of you have had this happen, or known someone who has?? Also, if you have been pregnant before, what symptoms did you have, if any, during the TWW??