TMI gas? Baby kicks?

But I never know if I'm feeling baby kicks or if it's just gas...that's really frustrating! My placenta is up front and I've been told that it will make the kicks feel less kicky at first and more like movement or bubbles or something...well I'm going to be 21 weeks on Thursday and I want to feel some kicks! Ha! So what do you think? Gas or kicks? Or a combo? If it's up above my belly button I assume that's gas or stomach for sure but below, I just don't know...