Implantation cramping

Hi ladies. Those who experienced implantation cramps , what did it feel like and around when did you get it ? Me and my husband had unprotective sex two weeks ago (week that my period ended) and these past three days I have been having mild cramps. Period like cramps but more mild and it’s surprising because I don’t get cramps unless I’m going to get my period the next day. I’m just so confused because I have irregular cycles most of the time so it’s hard to tell when I actually ovulated . What we’re your symptoms like ?

I also have been getting non stop headaches

Been exhausted as if I’m coming down with something

The first day I had cramping I noticed a thick but watery white discharge

Also I have been constipated ever since I got the cramps!!!