SKYLA IUD LADIES, HELP.

Let me start off with this: I have anxiety. Please don't make fun of my paranoia... Anyway: I got the Skyla IUD placed in July of 2017 (roughly 7 months in) I've had pretty regular periods..maybe 2 or 3 days off but still within range. I'm now 5 days late, my normal period symptoms are all here (I won't go into depth). My SO and I had sex in the middle of March WITH A CONDOM. I'm not sure if he pulled out or not (not that it really matters with a condom) I had my normal period in Feb...where the hell is my period?! I've taken two Clear Blue at home pregnancy tests..both were negative(slight peace of mind). I'm 21 almost 22 if age helps at all. I've read about people spotting and then never having it again..but I didn't even spot. I had a regular cycle last month. LSS: Y'all ever had this happen and I'm totally crazy and just need to chill out and accept my period just disappeared..right? My SO has been very adamant on reassuring me that I'm fine and I'm just being paranoid (We go through this if my period is an hour off) (I'm almost considering abstaining from sex because of the amount of stress it causes me to wait on Aunt flo)