Need some advice on this dating situation, please help?

Been dating this girl for about 6 weeks. When we first met, we talked nonstop on the phone and over text messaging. We got close very fast. The last 2 weeks or so, it seems like it's all been dwindling, as in the amount of phone talking we do and texting. When we do talk, it still good a good conversation. Thing is, it doesn't seem like she's quite as into it like she used to be, as in she isn't flirty, doesn't seem overly excited to hang out, etc. But, she still talks like she has very strong feelings for me, saying things like i'm one in a million, the best ever, she misses me and cant wait to see me again, how much she likes me. It just seems like her feelings don't match up with her actions. Last night she cancelled our plans at the last minute, saying she needed to stay in with a sick family memeber, and my gut said it was BS. Today, she didn't text me all day until just now, which was also a first for her. Should I break it off, or just ask her whats up? Opinions? Advice?Need some advice on this dating situation, please help?
my advice is.. shes one of many fish in the sea ...you learn, i think where u might of went wrong is been too n eedy from the start, girrls sense that, dont be the usual nice type of guy, ive tested this theory and i think assholes get more *** then the nice type, just tell her how you feel and see where it goes, if she gives u ****, move on, show her what you want, dont be boring and dont ever hang on to the girl like shes on some kind of a pedastal/trophy, always have the mind set ur what she needs, if things dont work out its her loss, and DONT CALL HER SO MUCH, UR A BUSY GUY (AT LEAST THAT WHAT U SHOULD PORTRAY, U HAVE **** TO DO).Need some advice on this dating situation, please help?
Ask her what's up. Tell her what you have sensed since a few weeks ago. Tell her to be honest with you. She sounds like something else has got her attention.