Is she mad at me? When should I text her?

Okay, so two days ago (Friday) this girl I really like & me hung out with her friend & this other guy. We went to go eat then went to blockbuster & got a movie. Ended up going to watch her brother play tennis & we played a little too. After that we went to go get ice cream with her parents cause they were there. I took her home, gave her a huge/kiss on the cheek & said we should hang out tomorrow, etc. you know? Then I texted her the next day & she was being really short and everything acting like somethings wrong. Her bff is leaving for 2 weeks so idk if thats what was wrong but I asked her and she said "yeah just tired." Should I text her today & see if she acts the same way or should I wait til tomorrow or for her to text me today? If she acts the same way what should I do? Ohh & she likes me too just to mention that. I also texted her last night after I didn't text her back just to tell her goodnight & I hope to see her soon. I thought it was nice but she didn't text back last night or this mourning & I know she was up when I texted her. Does this mean she's mad at me for some reason? I don't think i did anything wrong.