What should I do?Does it means I'm annoying?

A girl and I were texting and it goes similarly like this. Me: Hey Her:Hi M:Busy all week? H:Nah today yes was like hell M: Watcha mean H:(details) M: O.o H:Yeah Then I asked if she wanted to go to the movies later during the weekend. She said she was busy with a friend which was the truth. But the text conversation ended unexpectedly with her just putting hmm. And I texted back yea hmm...And I got nothing since, am I annoying her?