Threw up a white foamy substance this morning?

anartiststyle

I am in my second trimester, I will be 5 months this Sat. I have not thrown up this whole pregnancy but did feel nauseous during the first trimester. This morning I got out of the shower and it came on pretty quick. I threw up one little white looking thing. I suppose it could have been white because I had not yet had breakfast and there was nothing in my stomach? Just nervous because I have not thrown up yet.. this was a surprise. I felt great afterwards and like I said it was just once, not a long throw up. Anyone else have this?