This is certainly not a waste of time, and don't ever feel that anything that is bothering you is a waste of time because it is not, and there are always people to help. Alright, first off don't wait any longer to take action. Women can have up to 3 periods after conceiving and still be safely pregnant. You have to get on it now.
You're 17, so I'm going to go ahead and say there is really no need for you to tell your parents. However, before you do anything, even buy a pregnancy test, tell your boyfriend. If you're having sex you need to discuss the possibility of you becoming pregnant and what you would do in that case. The possibility of you being pregnant will upset and scare your boyfriend, but really that is the reaction that you should be looking for. Don't let that deter you from telling him, though. If you are pregnant, and even if you're are not, you are going to need him to help you through this. If you absolutely do not feel comfortable telling your boyfriend (in which case I think you shouldn't be having sex with him), tell a friend who will help you.
By now a pregnancy test should be able to tell you whether or not you are pregnant. I would buy two, just to make sure. If it comes out positive, and you have yet to tell your boyfriend, you better do it now. Keep in mind that, if he's a good boyfriend, he'll probably be upset that you didn't tell him in the first place and he wasn't able to help you out until now. At that point you hit up your doctor, or find a clinic in your area, and they will examine you and tell you for certain whether or not you are pregnant. If you are, there are basically 3 options that I would suppose you are already well informed on and should discuss with your boyfriend.
I strongly suggest you tell your boyfriend now. This isn't only your problem, and this is cliche as all hell but it takes two to conceive. Whether you think you'll upset him or what, it is his right to know, and if he pulls a "I'm not ready for this" and flees, then you know he wasn't worth it in the first place.
There's one more option if you'd rather not even take a pregnancy test and hopefully just bypass the whole situation. (Even if you decide on this I would still tell the boyfriend.) Go to your local clinic and ask for a morning after pill and a months worth of birth control pills. If you are pregnant this will induce a miscarriage.