Nausea/Possible early pregnancy?

Backstory: We suffered a miscarriage in February and started trying to conceive again right after my next cycle. My period started on April 7, so my ovulation was predicted for this past Sunday, April 21. We had sex 3 times this past week: 4/17, 4/20, 4/21.

The past few days I have been off. I feel nauseous/light headed all day and night and almost to the point of puking. I know it would be way too soon for pregnancy symptoms to appear, but is this something someone else has encountered?

Thanks!