Sex after baby

Hey mamas I hope you can help me or even suggest how to explain this to my dr so I get the proper treatment instead of being brushed off? So ever since I gave birth a little over 6 months ago sex has been painful. However, today I realized after starting my first period postpartum it’s almost only at the entrance of my vagina? I use a menstrual cup abd was expecting pain but inserting it and having it in I felt none, however when it came time to remove it I felt almost the exact pain during intercourse. Once I reinserted the cup I felt no pain but I’m sure once I remove it I will feel it again. Anyone else experience this and if so what helped?