Yesterday your boyfriend posted a thread about getting married next year and now you post this. If there's a problem with trust at this stage of the relationship then it doesn't bode well for the future.
When a foreigner asks you to marry them they are also asking you to make a lot of sacrifices so that you can be together in another country. So you really need to trust a man before making a decision like this. I don't think you really need anyone's advice on what to do here, your post says enough.
Good luck for the future.