What’s the chances?

I am just wondering if someone can advise me. Me and my partner dtd on Thursday 26th July and my day of ovulation was the following day (27th). On the Sunday I experienced period pains on and off about an hour maybe more. I kept thinking I have only just ovulated I’m not due on my period for like 2 weeks!

So my question is.... what could the period cramps of been? I have read you can have period pains when implantation occurs but I don’t think that can happen so soon after dtd can it?! Any advise or thoughts appreciated. Ben ttc for almost a year and I’m just worried something is wrong with me.