TTC while breastfeeding??? Help!

Hi guys! My husband and I just started trying for our next baby. I have a 5 year old and we have a 10 month old. First baby was a quick oopsie and my second we got pregnant with in one cycle. I have NEVER tried to get pregnant while breastfeeding, nor have I gotten pregnant while breastfeeding in general. This time, however, I am trying to. Do you guys have any tips for increased probability (don’t say wean please!)? My doctor said I’ll never know when I ovulate during BF’ding and it’s safest to just have sex every other day. I have an opk that I’m going to try to use anyways. Oh, and I should add that my periods returned about 3 months PP and are mostly a liiiiiittle irregular. Any advice or solidarity would be great! Thanks!