Help...

I’ve had an iud for 6 months and no period since like 3 months in of having it, but recently I’ve been spotting off and on this month for a few days each time. This is weird. My husband and I still use condoms, and as of a month ago my iud was in position just fine. I know this sounds crazy, but I’m having that weird light red and brown spotting randomly and I’m gassy, tired, my stomach hurts, I’m not feeling great lately. I took a preg test that was negative but I’m worried that I could still maybe be pregnant? Am I too paranoid? Is this just normal for an iud? It’s a hormonal iud liletta. I took antibiotics (Amoxicillin) the first week of May... does this affect it?