IUD out of place?

I have had my Mirena IUD in since September and it’s been free of any noticeable abnormalities thus far. Today during sex I felt an unusual amount of pain and had to stop to lie flat on my back until the pain subsided. It is now hours later and there is still some pain. About a week and a half ago I had some pain and had to stop as well but the pain disappeared quickly and I don’t think the two pains were particularly similar. I went to feel my strings and I can’t tell whether or not I’m making it up in my head but they definitely feel longer. I don’t know how soon I would be able to get in to see my Dr. and I don’t want to take this to my parents if it’s not out of place, because I have a habit of being kind of a hypochondriac. I’m scared so please don’t make me even more scared but I am not sure what to do and I could use some guidance.