Sleeping with someone on the first date can be a problem

These days most people choose to search for a date on the Internet. This can be both good and bad it depends on what your looking for.
If you're just looking to get laid then its pretty simple. You hit it and then you quit it. Simple right?
On the other hand if you're looking for a relationship. It gets much more complicated.
What I have learned the past year or so is that if you make the mistake of sleeping with an Internet date on the first date it may do more damage than good. I know this sounds old fashioned but, it can only help the relationship if you get to know each other a little better before you sleep together. In my case, I am looking for a relationship. I met someone on line and we chatted. We seemed to get along really great. We had our first meeting and again we were getting along good. Before you sleep with someone, there really aren't many expectations. After you sleep with someone the expectations are phenomenal. For example: Before you have sex and you don't speak for a couple of days, no big deal. After you have sex and you don't speak for a couple of days, the conversation might go like this "Why didn't you call me?" or "I called you and you didn't answer". In other words you're expected to talk to each other on a regular basis after sex occurs.
In my case I'm the sucker this time. Because I met a lady that I'm really not that attracted to because she's a little heavy and had varicose veins which really turns me off. But, for some reason I really want to spend more time with her. Every time I call and she doesn't answer, I'm a little angry. This is really out of character for me, so I've decided to take a step back from the situation. Yes, we did sleep together on the first date and the sex was OK but then again it was really dark so I couldn't see the things that I didn't want to see. I'm not saying that I'm a show stopper but, hey, you like what you like right? I'm sure there are things about me that people would not be attracted to and I understand that.
If we would not have slept together so soon I wouldn't have been concerned if she didn't answer when I called. Now that we have, I expect her to be available to me when I want to contact her. You may be thinking, she doesn't like me and she's blowing me off. You might be right. After 3 weeks of speaking almost every day and then suddenly not speaking for 4 days. Clearly something is up. So for the sake of my heart I will take a giant step back and move on.