Period

I have been trying to get pregnant for about 4 months. My period has been pretty regular for a couple years. My last period was 10 days late. This time I was suppose to get it last week, I had pms Symptoms and crampy so I was sure I was going to get it. Then nothing. Then this week I had bad cramping so I definitely thought I was going to get it again and nothing. I have taken a test and it is negative. Is this something I should see a dr about?