I need advice..

So my boyfriend has mostly female friends. And he went up to stay with one of them that I have never met who lives about 2 hours away. Normally that would be fine but he has been with her all day.. Just the two of them. I want to trust him. And I mostly do but it really hurts. And now I find out he is staying the night up there. He knows how much it hurts me but he won't come back. Am I being too jealous?