Vf bfp BUT idk how to calculate a date due to an irregular period

My son is 10 wks old. It was a long 2 year journey to have him.

I haven't had my period since he was born ... Feeling a bit off the past​ few days I took a test, then another and another. All faint positives.

I have no idea how to determine a due date or ovulation date or implantation.

Here's what I know around the 16-18th I had ewcm discharge. A lot!

We had sex for the first time since having our son on the 23rd and 25th... Afterwards I did the math and thought we were safe cause I would've had to have O by then judging by when I had the ewcm...?

Then May 4th and 5th I had light cramping, I figured my period was coming BUT nada!

So, the 8th I took a pregnancy test and got the super faint bfp.

So now I wonder IF the cramping last week was implantation?

And, how long after ewcm does someone ovulate? I thought it was 24-48 hrs.