Cramps after period!! HELPPPPPPPPP IM CONFUSED

Last day of my period was the 13 but on the 17 I started having cramps mostly on one side took an ovulation test and negative I also had a lot of discharge that day. Today the 19 mild cramps again no serious pain but I feel they are there also feel the sensation of having to pee. We have been ttc for 3 months now so I’m confused please help