IUD and Cycle Length

Has your cycle length changed with your IUD? I have a hormonal one and sometims mine is different. I know sometimes you can still ovulate so I trying to figure out if thats what my spotting was. But it was almost 3 weeks after my last period in June and the spotting was on the july 18th. And I still have started yet. (3 forms of birth control used when I had sex IUD, condoms, and withdrawl so I dont think its that) i have been really stressed thinking there was some chance I was pregnant because thats how my anxious brain works.