Unusual bleeding

I was on birth control (Nexplanon Implant) for 9 months. For the whole 9 months I never had a period besides right after I got it implanted. I had it removed last year in July and at the end of December and beginning of January my periods started to come back they were normal lasting about 5 days. Started last month I had my normal 5 day period and two days later I started to bleed again it wasn’t really heavy but more so on the average to light side and that last for about 12 days. In between those 12 days I went to see my doctor she barely checked me and just told me that she is happy about my periods regulating and if they become abnormal to come see her again. After the 12 days I stopped bleeding again and it once again came back for 5 days. After the 5 days I waited to tell my boyfriend and we had sex last night and I started to bleeding during and after. Is this common to happen after the Nexplanon implant? Has this happened to anymore else and if so what did you do about it?