It’s not completely obvious what is going on

My husband and I are ttc, and every other cycle we have tried it has been VERY obvious that we were out that month. I have irregular periods, but when they come, they come in full swing lots of bright red blood and lots of cramping. we use opks to give a better idea and I had an almost positive on the7th, 8th and the 9th, the 10th was negative. We bd on the 8th and the 9th. Fast forward to now. About 2 days ago I started spotting but it was very little and very very darkened and had some stringy looking bits in it. No cramping. Not even enough to go through a pad in a day. It seems to be slowing down now but I’m confused as to what is happening. It this af? Is it implantation? I took a frer this morning and I thought I could see something but I have terrible line eyes and have been the bad luck for evaps. I’m trying to be hopeful but I don’t want to be disappointed!