Trying to get pregnant again

My husband and I decided to start trying for our second child. Our son is 13 months old and we decided to not fall force it (i.e ovulation tests) until after he’s 16 months. Most doctors suggest waiting 12-16 months. I did however start tracking my periods again. I’ve constantly been skipping every other period. How long did it take you to get back on track after your baby? I just struggling with negative tests and unreliable flows.