"Flutters?"

So, I got up this morning around 4:45 A.M. to use the restroom and when I laid back down I swear I felt baby doing something. My Lil' Peanut has always been on my right side and I just had a Doctor's appointment last week and heartbeat was found to the right of my belly button. What it felt like was my baby was tickling me from the inside. I am almost 15-weeks and they say you can't feel "flutters" until 16-20 weeks. I know it was my baby moving around, already letting me know that he/she is okay.