Ladies HELPPPPP MEEEEEE!

Summer

First of all.. I'm pretty new here and I'm absolutely BLOWN AWAY by this incredible app with such supportive and sweet women that are truly here for eachother. my excitement is through the roof. now.. I have a 5 year old daughter (who wasn't very difficult to conceive) and her dad and I have been TTC for about 3 years now.. but the tricky part is how IRREGULAR MY PERIOD HAS ALWAYS BEEN! So its nearly impossible to guess when im ovulating.. for as long as I can remember, my period would be completely RANDOM.. I might go 2 or 3 months without a period at all. then when I did it would be so heavy that I would soak my bed during the night. (I ALWAYS STARTED IN MY SLEEP) but the last few months (roughly 5 or so) iv had one every month but I got so use to not being able to calculate my cycle.. that I can't recall what day I start and stop on.. although I have noticed its always towards the beginning of the month and is a light to medium flow lasting about 2 or 3 days. my husband and I had unprotected sex 3days ago on SUNDAY the 20th (MAY) and I would LOVE your advise on when to test.. when I could have ovulated.. etc. what's completely overwhelming for me is that RIGHT AFTER we had sex on SUNDAY.. for some reason (we BELIEVE the grace of GOD) we BOTH felt this INDESCRIBABLE feeling of conception. like there is no way it didn't happen.. we haven't even stressed about conception in several months or even talked about in several weeks because we came to the realization that its very possible The Lord just doesn't have in our plan but for some reason.. it came over us like nothing iv ever felt before. help. me. mommas!!!! Any thoughts on ANY OF THIS will be so greatly appreciated. Thank you for your time and for your compassion for the worlds most impatient woman EVERRR!