Iud and periods?

I got my IUD beginning of December. I got it like right at the end of a period, then bled for the next month. Right at the 4 week mark I stopped bleeding. I’ve gotten a little bit of spotting here and there since then, but haven’t had another period. Is this normal for a hormonal IUD? I have Liletta. All sex is protected with a condom still and I can still feel the strings. Should I be worried and take a test just in case? Learning to trust this thing is hard! I was on birth control pills prior to this and now I am getting symptoms like sensitive boobs, for example, that I’ve never had before.