Relationship Help

So, I've been talking to this girl since September of last year. We'd been on and off texting for a while, but nothing too much, no more than friends would. Recently, through one way or another, we've been a lot more frequent in our texting. During the Easter holiday period for example, we had been texting since mid morning to late evening. We've talked a hell of a lot, and I recently went on a trip and messaged her everyday, and the signs are looking good, as I was deeply into her at this point. The day after I come back, we arrange to meet in our town centre, just the two of use. We spent like 3 hours together and it was really fun. Bearing in mind, by this point, nearly all of the advances have been from her, although I made it clear that I was reciprocating them all. However, around three days after our trip, she mentions in passing that she has a boyfriend. I try to the best of my ability to gather extra information about this, and I originally thought this was a (somewhat petty) plot to make me jealous, to see if I would make a move. As such, I continued to message her, and made sure to keep our conversation flirtatious. Now, though, I am convinced that she truly does have a boyfriend, as not once has she ever slipped up,

I really like this girl. A lot. But I need to know if she's playing me. Any advice would be greatly appreciated.