Is she interested or not? What should I do?

I have been seeing this girl for roughly 4 weeks, she message’s me instantly all the time. we’ve kissed and slept together, she even confessed to one of my house mates on New Years that she really liked me but apparently didn’t want to say to me because she was scared it might ruin things. last time I took her home it was like she didn’t want to get out my car and kissed me a lot when she got out and texted me first after.

What plays on my mind and confuses me though, is when we make plans something sometimes comes up, in her life that we can’t go. My gut tells me she’s not telling the truth sometimes. This has happened before and after we’ve had sex so it’s not a sudden thing.

My thought process is she’s scared to get to attached thinking I don’t feel the same way.

Or

She’s not actually that interested and she’s stringing me along

Or I’m just seriously over thinking it

And I need to know how to react, what’s your thoughts?

She might be playing games, possibly trying to not look too available so she cancels.
People get worried about their image, if they're too available, they think you think that they're not as desirable.

I know it's ridiculous but people will do that, I've done it before to a degree in all honesty.

"she really liked me but apparently didn’t want to say to me because she was scared it might ruin things"

That's my evidence that she's that type of person. Not acting completely genuine.
I'm not saying that makes her a bad person, it just overcomplicates dating when things can be so effortless and easy.

Yeah man, when a girl does those things she is clearly not interested. You should probably just forget about her and move on. Syke... Are you just showing off?

See, there you already got two very different opinions. Which, funny enough, does well to illustrate my opinion on this one. I don't really think this is one where we or even you can necessarily know this for sure. It could very well be that she's just nervous she'll seem TOO available and scare you away, so she feels she has to play these kind of games. In other words, she may be very interested in you, but worried she'll scare you away if she's too eager.

BUT... unfortunately, it could just as easily be that she's not interested, but she just currently enjoys getting something from you. She enjoys the attention, or enjoys the romantic parts (kissing, sex, etc.) but doesn't necessarily want an actual relationship.

We can't really know any more than you can. So, really, I think your best bet is just to worry about what YOU want and go about pursuing that. If you want something serious and start to try to move things in that direction, I think it should start to become obvious enough if you two are on the same page. If it comes down to it and you deem it necessary, also don't hesitate just to ask her. Just talk about where you both see the relationship going. Maybe she won't be honest with you, but maybe she will. If she's willing to be honest with you, then either you will both be on the same page (and that is great) or you won't be, but so much better finding that out sooner rather than later.

Good luck to you either way. I hope it works out for you.

Well what I don’t get is
What keeps you from discussing that with her?