April 28th last period Husband is fixed. Help?

My husband got fixed 2 years ago. My last period was April 28. No, I did not cheat. My question is, is it possible for a woman's period to change its cycle from 32 days to 43 days in one month? Or is there actually a chance that I'm prego?!? I'm having light twinges. I broke out in pimples and my are sore, like I would start my period any day. However I am having a clear constant discharge...