You have to get tested, but not right away. HIV takes a while to show up on tests. If you get tested now, it is too soon for it to show up, so it would say you are negative either way. You have to wait about six weeks. If you test negative after about six weeks, wait a few more and test again. That means you will have to go for some time waiting and wondering. You will have to be very careful and always use a condom for a few months so that you do not infect anyone else if you are infected.
As far as being circumcised goes, researchers are still studying the relationship between circumcision and HIV. Some researchers say circumcised men have a lower rate of getting HIV, some say they have a higher rate, and others say it all depends on what country the study was done in.
Whether you end up testing positive or negative, be safe in the future.