No period but fertile CM

Hi there, I am currently breastfeeding my 18month old. I still haven’t had my period yet. I had what seemed to be fertile cm last week with a few left pelvic cramps prior to that and I took a ovulation test and it was close to positive, but negative later in that afternoon ,maybe I missed the surge but we did have intercourse the previous day. Do you think I ovulated or is this normal to get these when breastfeeding and not actually ovulate? Any opinions appreciated. Thanks in advance.