Good, I am glad he got tested. Not to be rude, but are you sure, were you there? Or did he just tell you?
That only comes out of my experience with men. So nothing against you or him, just food for thought.
He may be right about the ovarian cyst, which is even more important about why you need to see a doctor, they can be excruciating if the burst, not to mention life threatening. But if you just started with these symptoms, it probably is not that bad.
Home pregnant test? Yes, it may be a good idea. Now it is important that you do it first thing in the morning.
You have to do it first thing in the morning because that is when the pregnancy hormone called hCG is in the highest concentration in your urine.
I do have to say that you are doing great by making sure you are protected. Good job and keep up the good work there. I am also glad to hear that he was your first, at your age a lot of gals are not like you.
Keep me posted as to what you find out, or if you have any questions, please do not hesitate to post again.