I am so scared

I found out 2 weeks ago that I was pregnant. My hubby and I were over the moon as we have been trying for 15 months following a missed miscarriage in October 2014.
Last night I had sever cramps for about 7 hours. They were painful and came in waves every few minutes lasting for about 10 seconds each cramp.
This is exactly what happened to me the last time I was pregnant before my early scan which showed a missed miscarriage.
I am 5 and a half weeks pregnant and I just know I've lost the baby.
I don't know how I can cope with this again