I have no fallopian tubes but for two days now i have had cramping and spotting, i have also felt dizzy when getting up to fast.

Dehydration: If you are dehydrated it can make you feel faint when you get up too fast. Cramping and spotting are common during your periods, and if you have no fallopian tubes it's very unlikely you are pregnant - but if concerned about it, take a home pregnancy test. If it's positive, see a doctor ASAP, it would be an ectopic pregnancy that can be dangerous.