Skyla IUD

Beans
So yesterday I got the Skyla IUD put in.... And it reallllly hurt for me but it was short so I got over it.... Anyway, before I got it, I read online that it couldn't have any affect on your emotions or weight gain or acne, but last night I was reading peopel say they have terrible mood swings on it and the break out!!!! I have a really clear face and I don't want to mess that up, and I don't want mood swings.... Also I read people come up pregnant without knowing because they had the IUD....Is that because they just didn't check if it was in place before sex?? Because my doctor told me to always do that, and I was wondering how long after getting it in can I have unprotected sex (with my bf that I know has no diseses) and are these even really good??? Ik they are the most protected form of BC, but seems VERY easy for them not to be in place and then you get pregnant.