I wouldn't think the nausea would be from being pregnant yet

I've always heard that the nausea doesn't really set in until about 2-3 weeks dpo
But I would think you could be O'ing early. Are your cycles normally 28 days? It could also be your body gearing up to O. I get pain in my back/side and EWCM for 2-3 days before I ovulate.
HTH