TTC after July 6th MC

I found out I was pregnant June 28th, but started bleeding July 6th and miscarried around 6 weeks. I miscarried naturally and bled for 6 days. I  had scheduled to go in to my midwife for a 8 week appointment last Wednesday, and still went but just for a gyno check up. My husband and I got the go ahead to keep trying and we have been TTC ever the bleeding stopped.

I invested in a bunch of ovulation test strips and I've been testing for about two weeks. I tested in June which helped me get pregnant. They were clearly negative until yesterday morning when I got a positive. I know I don't have to keep testing but I have been. I tested today and my strips looked really close but hard to tell for LH surge but when I looked later they had all darkened up. Technically the instructions says not to read after 5 minutes but these seem to take forever to darken up. 

Question -- since the tests aren't telling me when I actually ovulated but just when my LH surge is, when do I start counting days past ovulation? When my LH surge goes back down?

Thanks! ❤️💜💙