[Always *]

There are early pregnancy tests, they ARE more accurate if you give it a while to give your body and hormones to catch up with the whole "holy cow I am pregnant" info. So yeah, but you can definitely give it a shot.
Worst comes to worst, if you are in a place that having a baby wouldn't be the worst thing possible, I'd just keep an eye on your period the next few weeks, and if your noticeably late/ it doesn't come, definitely get a set at that point.
And you can usually go to a walk-in clinic... I think you may call those free clinics in the states, but that might be a whole different thing for all I know haha (either way though...). Also, you can call around. I think most GPs would be able to do a basic pregnancy test so call around too