Nexplanon help!!

So I got the nexplanon implant after I had a unusual reaction to the pill (a layer of skin grew over the neck of my womb which was causing me heavy bleeding constantly). I had this removed by colposcopy and my Dr recommended the implant. I've had a couple of 'period' like bleeds. However I'm getting quite bad cramps with light brown mucuousy discharge. Is this normal? Has anyone else had it. I googled it and it said about STIs which I defo haven't got as I've only been with my partner and we've been tested. It said that this discharge could be due to hormonal changes, however I'm worried that I might have an infection from the colposcopy. Please can someone help me. Thank you xxxx