My tubes are tied what's going on?

Heather • I`m 29 with two kids a 5 year old girl and 2 year old boy have been married 6 years and my husband`s name is ezequiel.
I have had my tubes tied since 2013 and this month I cramped and cramped like I was going to start but I haven't. My period was due on Tuesday and well today is Friday and still nothing but my back is cramping please tell me I'm not pregnant.