This might sound wired but I felt the baby inside and seen the baby outside and I was only eleven weeks and two days. But at the same time this is my sixth pregnancy so you tend to feel more earlier then normal. To answer your question it was your baby, and that burning feeling it's either the food you ate or the stomach growing.
Ligament pain @kelseymaria
The skin or inside? Probably just stretching either way.
I am having a burning feeling on the left side of my belly right now..any ideas?
I figured it was baby because it was a feeling I've never had before and I weigh 107 and my belly is protruding quite a bit
Tingly sounds more like something else, but it's possible it was baby. We can't really tell you because we didn't feel it, it doesn't feel the same for everbody. Some people says it tickles like butterflies or bubbles, for me it's more like a goldfish swishing. 15 weeks is a tad early for FTM, but definitely possible.