helppppp!!!

So quick question. I was on the nexplanon for 3 years, then the Mirana for 6 months. I had no Af the whole 3 years on nexplanon but when I switched to the mirana I had a Af every month. Had my mirana removed January 15th and had Af the 17th-20 never got a LH surge and didn't have Af again until the 28th of February until March 3rd I think my cycle is finally starting to get regular again. Because I did have a LH surge this cycle. Pink pad has me starting Af in 18 days but that seems like a long time to wait if I'm already 7 dpo. When do you guys think I should expect Af? I'm so confused because I used to have a regular 28 day cycle and now it's been all screwed up. TIA!