this girl needs some input, help!

Genevieve
Hiii friends! I need some input... (I have a doctor appointment this upcoming week but I'm nervous enough and with basic insurance it's still a lot of money for tests) 
Let me start off by telling you all I have the Skyla iud and a long term significant other. The IUD has been great except for lately. My period has been wonky the last 5 months with either random spotting around my period time, just a day of my period, or full on shark zone.
 This month my period is technically 11 days late but when we had sex I bleed during intercourse around the time of my period. Not just once, but everytime we had sex. (We were on vacation 8 days) I thought I got my period but no blood on the tampon etc. I had the Back ache, bloat, and cramps to go with it. Just no blood, except during penetration. How weird is that?! Anyone have any ideas what's going on? 
Thanks in advance.