How come my periods are getting shorter?

Way over a year ago I had a 'pregnancy scare' that really messed up my cycles so for a while my cycles were 32-35 days till my past 3 cycles have been 29 days, 28 and 27. Before my period came messed up my cycle was 28-29 days but I didn't realize it could take so long for my body to normalize. I was on BC multiple times but stopped talking it because it just wasn't for me so is it normal for my periods to get that short? Don't think I ever had a 27 day cycle in my life!