Need Advice- This Cycle is Crazy!

So long story short, I’ve been off birth control and trying for 5 months. My cycles have been weird: 36 days, 29 days, 37 days, 34 days. And this cycle I’m on day 40 and counting. Every other month, I was able to get clear positive ovulation tests, but this month I couldn’t and stopped taking them around day 25 since I figured I just wasn’t going to ovulate this month. Based on my body, I feel like I ovulated 10 days ago. I typically start my period 10 days after ovulation, so today may be the day. About 2 days ago, I had severe cramps for about 30 minutes and figured it was period starting, but I haven’t had any period symptoms after that. I tested with First Response and got a negative. I just don’t know what else to do or think! Anyone else have anything similar happen? Thanks for any advice!!