Ttc over 36

Hi I'm almost 36 and have been ttc since November 2012.

I had a mc in april and I normally have longer cycles between 33 and 35 days. since my mc my cycles have been 33 days then 31 days then 28 days. very strange for me. so now I have no idea if I'm ovulating normally at 21 days like before or earlier on cd 14 like last cycle.

opks have been randomly done and never positive. and my ovulation pain started around cd 14 but lasted until cd 18. I'm currently cd 20 so I guess I'll know in a week or so if it's 28 days again.

starting to feel my body hates me