Is it normal for my friends to treat me like this?

I have never been in a love relationship before. I met my first and true love in my university. We both love each other dearly. He is same age with me.

Before we coupled up, we were in a big group of friends. There were 8 girls including me and 5 boys including him. My bf had a crush on me since the beginning of the semester. After one year, we become close and fell in love with each other. He expressed his love for me and i accepted him happily. when i shared about it with our group of friends, they sounded happy for us. but after sometime, they seldom talk to me. I used to be the closes to them. But now it seems like they are avoiding me. i feel they have completely forget about me. To make it worst, they are treating him in the same way to... before we couple up, these group of friends will text me, poke me in facebook, write on my facebook wall that they miss me, forward frienship messages and i also will do the same. but now, even if i do that, i could feel that they are not responding in the same way they used to. Now, I have been in relationship with my bf for 10 months and i feel lonely whenever i am not with my bf because once i get into the girls hostel, i cant feel the attachment with my girl friends anymore. Even when we meet each other when going to classes, we greet each other like a stranger. My bf said things will get better and i should not change the way i treat them even when they change. he advised me to follow the flow. But is it normal? i am scared. Is there anything that else i can do about it? please help me...