I think I'm not fertile

Rimini
I was on the implant for 2 and a half years and before deciding to come off due to weight gain and mood swings. Me and my boyfriend of 2 years find it really hard to use condoms and most of the time just forget about them. Each time we've had unprotected, I've had my period a few weeks later. Each time I thought there might be a possibility of pregnancy but each time nothing. Could there be something wrong?