I spent time with my crush during the weekend and asked her out. She said yes, and we decided to plan the date later as she's pretty busy during the next week or two. Before I asked her out, she had been texting on WhatsApp with me all the time, but now she has started to act different: she didn't answer me at first and when she did, they were just simple short answers, unlike before when her texts were full of life. I'm confused, what does she think? She might be busy, of course, but does this mean something?