Trying to conceive baby #2

Isabel
Hello, my husband and I have been trying for baby #2 for about 3 years now. We had our first daughter when I was 17 she is now 7. When I had our daughter I weighed 115. I have irregular menstral only way i would see it was with provera. I recently went on a weightloss journey and I have gotten my cycle 2x in the last 4 months with no medication which is odd for me. I started at 224lbs and I am now down to 185. How do I know when I ovulate if I don't see my cycle monthly. Dr ran blood test and everything came back normal so he is giving me 6 months to try this on my own with weightloss. I am feeling the stress and agony and some much pressure just trying to get pregnant. I just don't understand my body. Any advice? Anyone going through something similar?