First clomid cycle!

This is my first cycle of Clomid (5-9) I'm on CD20 of 28. I had a positive opk on the CD14 and CD15. Thinking that I probably O'ed on CD16 so I am now 4DPO. Has anyone had any side effects at this point? Up till now I haven't really had any, but today I had  a wave of a hot flash and nauseous  like you would not believe. Also I feel like I'm about to start my period any second..light cramps on both sides.