I have noticed in the last week now that I have had a constant yellowish discharge from my penis. It seems to be worse after ejaculation but every morning I find yellow stains on my sheets. I am worried that it may be an STD but it started just as I began my travels outside of the US and my diet is not near the same as it was back home. I can't get an STD screening done until I make it back to the states and I am just very concerned as to wether I could have an STD or not.