I agree with Chris that nothing will happen for sure until after he takes this big test. If it's an exam which will impact his future (location,
profession, earning potential...) then he would certainly not want to
make major life decisions until after this is over. Also, I think it's very important to try and avoid major discussions about the relationship before the test. If he cares very much about this thing, then let him do it as best he can; you don't want him to think forever afterwards that he would have done better if he hadn't been upset at you. For that matter, if you're thinking of a future together, you obviously want him to do as well as he possibly can on the exam, which few can do if they're in the midst of an intensely emotional struggle. This doesn't mean you shouldn't stand up for yourself, but this isn't necessarily the time for "big talks about Us".
So if you're thinking about possibly a serious relationship, I'd suggest keeping
the next few months fairly low key. Observe him, observe yourself with
him. Don't rush to judgment yet. Enjoy the beginning of this new experience, and give just as much as you feel comfortable giving; don't give out of an expectation of return. You have a grace period; don't get in deeper than you wish, but this doesn't mean you need to restrain yourself. Just try to figure out how deeply he resonates with you, and who he is, and what kind of life you might have together. Forever is a long time. It's worth taking things slow and enjoying the process.
Obviously, you need to be careful, and you ask a lot of very good questions. But I wouldn't say things are clear yet, or that one can expect them to be. Men aren't necessarily certain about things any more than women are. Sometimes we expect them to be because society gives them a certain amount of authority. But how would you feel if there were a childhood friend of yours you knew wasn't a good match for you -- but whom you cared about sentimentally? Would you move on to an adult relationship or constantly answer the siren call of the past? Most everyone, answering honestly, would say that the answer is not 100% obvious: it requires a decision, and a choice to create something from one's life rather than simply allowing things to happen. As Chris said, this is also a choice which the two of you might make together.
Good luck -- keep us posted.