Not inviting you back to their house. Only giving you their beeper number or cell phone. Not being available the usual times other people are available, like weekends and evenings. Coming home late. Starting to exercise.
Women tend to glow.
Think back to the way we were behaving when we were first having a relationship. That's what you'll find. Most people are hoping for the best, and when they find out it can be very distressing. It has to be met with a lot of sensitivity. Yet they also can have a sense of relief.