Hi, and thanks for your medical question on eHealth forum!
Stomach cramps around 2 weeks after your last period could indicate ovulation time and this is the time you should try to conceive. However, if the cramps are so severe, it could either indicate multiple ovulations (if you are taking any medicine) or it could be due to irritable bowels.
If the cramps are due to ovulation they will settle down once you ovulate. If not, they may persist. Please consult a doctor then. Hope this helps. Take care!