It may be as AKA_Monet said that some ladies are really not ready for marriage and serious committment just yet. Just because friends and family members are in relationships doesn't mean that it's your time to be also. If you are praying for it, then know that the Lord answers prayers in
HIS time not our time.
Right now, you may need to focus on other areas of your life that would be sacrificed if you were married. Marriage is a completely different lifestyle. Also, the Lord may be preparing your husband.
He may not be ready for you.
My husband and I have known each other since we were 16. We dated at that time, but broke up when we graduated. Well, when we got back together years later, it was obvious that the Lord meant for us to be together. We got married 6 months after we started dating again. However, if we had married before or even stayed together we wouldn't have grown to become the people that we are today and were when we got married.
So, just be patient. The Lord has a plan for you and your life.