Advice needed

I’m 7 months postpartum and still exclusively breastfeeding. My cycles have been somewhat normal: 33-36 days, and I’ve always had a heavy flow period. This month I had some brown discharge/spotting from about 24-26 of the “cycle days” but it never turned to bright red blood and it wasn’t even enough to need a pad. I just noticed when I’d wipe. It’s now day 36 and there’s no sign of my period and all the tests I’ve taken seem to be negative, with a few here and there that have a faint line which is most likely an indent. It’s driving me crazy because I’m wondering if I ovulated late and that spotting was ovulation/implantation bleeding and now I’m pregnant, or if I just had a super abnormal period this month. I’ll probably keep testing to see if the lines get darker but I just wanted to post to see if anyone had any ideas or had this happen to them?