First time Clomid

We have been ttc for 3 years diagnosed with Pcos. My Ob/GYN put me on clomid from 5/9 and i start ovulating on 14 of my cycle. Now from the past three days im having really bad cramps, feeling nauseous, headache, tender breast, and too much hunger.. So today in the morning i did mypregnancy test and it was Neg.. I was wondering if this is normal? Or should i take a pregnancy test again in 3/4 days?