Weird cycle and ovulation

Hi everyone!
I’m dealing with a bit of a weird issue for me, and I thought I’d try asking here before seeing my GP...
I stopped the pill in May 2017. But after that, I’ve been using contraception safely. Since this year, we’ve been having unprotected sex on Sundays (church day) and for the first time on Friday as well.
My cycle is usually irregular, ranging from 29 to 33 days. Last cycle was suddenly 26 days. I can clearly feel my ovulation and have very noticeable cervical mucus, which stops right after ovulation.
Now, I’ve had a bit of a messy stomach for two weeks, my intestines are sometimes giving me trouble, and in the evenings I barely have an appetite and feel a bit nauseous.
I think my ovulation was last weekend, but for the first time it wasn’t really noticeable—no cramps, no drop of blood, and not particularly much mucus. There’s still some mucus now, but not a lot.
Could it be that I didn’t ovulate, and that’s why everything is off? Does anyone recognize this?
Thanks in advance!