Conceiving I’m the same cd

We conceived baby 1 & baby 2 (ended in miscarriage) on cd21- hoping that’s my magic number this month as well. I am cd19 today so we are doing lots of bd until Sunday. Here’s my question- is that actually a thing? Like is “your day” the same time every month? I have a pretty usual cycle 29/31 days but I’ve never used opks on a cycle we didn’t get pregnant so I’m not sure if I actually ovulate that same time every month or it’s just been a coincidence those 2 months.

Also do you bd every day/ every other day/ 2x a day?

Anyways send some baby dust our way this weekend I guess?