Morning sickness?

I've been nauseous and vomiting for the last few hours but I'm not sure if it is due to morning sickness or this constant coughing I've had for the last two weeks. My husband has been away at sea for a few months and he came home one week ago so you can imagine how much coitus has occurred. Unprotected and no birth control of any kind. Is it possible to be pregnant ?? We aren't trying to convince at the moment so he pulls out but I know it's possible to still get pregnant from precum. (Also I'm on my period)