TTC while breastfeeding

I breastfeed my son & just got my first cycle back last month. I bought a first response ovulation kit and we had sex the 2 days before and on ovulation day. I took 2 pregnancy tests right before I should have gotten my period this month and they were negative. I’ve only had one period since having my son so I don’t know if my cycle is still out of wack, even though the test said I was ovulating. I’m 2 days late and don’t have a single pregnancy symptom so I know I’m not pregnant. (Felt multiple pregnancy symptoms right at 2 weeks last time). Now I’m wondering how to tell when I’ll ovulate again or if I’ll even be able to get pregnant since I’m still breastfeeding. Anyone go through something similar or have any advice? Thanks so much!