AF was due yesterday and for the 2 days before I had very bad cramping so I was convinced she was well on her way. I'm now 13dpo and no AF, did a HPT on 12dpo(yesterday) and got a negative result. Don't feel at all pregnant and I have missed periods in the past, but have been regular recently (for the last 6 months at least) though I have put on 20lbs since losing my boy at 19 weeks in Sept 09, so this could affect my cycle. Should I keep testing and if so when should I try again?