Ovulation

So I also use the app, Flo. I use this for community talk and all. Anyways flo says I'm 8 days away from ovulation, but I'm cramping like my period is coming. I had my period recently. I'm very moody, crabby, emotional and depressed. Could I be close to ovulation? My cycle varies from 28-31 days. My cycle last month was 31 days. It's been 31 days more often than not. What is your opinion?