I have been nausea before and after i eat anything. i had sex when i was ovulating, could i be pregnant or could it be something else?

Yes and yes...: Are symptoms related to all or some foods? Is volume or temperature of food a factor? Do your symptoms occur with every meal or only later in the day? Do you have associated vomiting (with or without blood), biliary colic, tenderness, stool urgency with meals, blood or melena in stool? What can you do to resolve the symptoms? Could you be under stress? Check pregnancy test to address 1st quesion.