It doesn't sound stupid. You just sound worried.
Babe, if you're young, your period may not be exactly on schedule every time. It can take years to even out, and even so, it may not start on the same day every time. In addition, as you probably know, stress can cause your period to be late.
If you're really worried about this, it might be a sign that you're not as ready for sexual activity as you thought. And that's okay. Nothing says you have to do what you're doing with your boyfriend now.
I think it might be a good idea to check out these three things, sit tight, and wait for your period. In the future, though, you can be better prepared. See:
Ready or Not? –The Readiness Checklist
First Intercourse 101 Safe, Sound & Sexy – A Safer Sex How-To
What's The Risk? - Five Easy Pregnancy Risk Assessment Flow Charts
"Maypole/The ties that bind you will unwind/To free me one day/And everything decays..." - XTC, "The Wheel and the Maypole"