5-7 DPO & absolutely exhausted!

I’m not sure how far past O I am as I didn’t opk or bbt 🤦🏼‍♀️ (silly, I know!) according to my apps (I use 3) I ovulated either the 16th or 18th. I had O cramps for both these days and the one in between so I have no idea when it was🙈 BD 15th & 17th. I’m aware it’s a bit soon for any implantation symptoms, but I have gone from being up until stupid o’clock every night as I’m a bit of an insomniac to being absolutely exhausted since yesterday. I napped during the day yesterday and went to bed at 10.30, and today it’s 9.20 and I’m so tired I feel ill. Is this normal? Anyone else has this?

I’ve had other symptoms too but I know they’re all PMS symptoms too so trying not to hold onto hope 🙈 1st cycle TTC after being on combined pill.