missing period with Mirena

M
So I'm supposed to start my second period with Mirena (got it inserted on May 8th, had the first period with it on May 28th). Now I'm supposed to have it again but I don't. I do however have some breakouts, very minor cramps and my nipples are sensitive. I'm calmed with the fact that I feel sure I'm not pregnant. My boyfriend doesn't even finish in me. 
So how do you ladies cope with not having your period? I mean, part of me is a bit worried. I don't know how to explain it. It's like 50/50 (half sure I'm not pregnant and half worried)
Also I had my check up last week and the IUD was in place.