How would you feel and what would you do? 2 of your friends almost ignoring whole friendship group.?

Your really close to a friend (lets call her Anna) you've had since primary school, been friend for 5 years along with 2 other friends and have recently drawn close in the last year to 2 others, one, lets make up a name, is Jane. Your friendship group has 10 people in it including you. Anna and Jane have slowly become really good friends, your fine with it. Anna, Jane and you are close because you share similar problems. Conflict arrives when they start ignoring the group and you, going off by themselves, being secret. You know they arent as good friends with the rest of the group but feel annoyed at them, you think their time together is becoming too regular.You still talk to them, sometimes it seems like your still great friends with both of them other times it doesn't. They don't seem to notice anything. The rest of the group do. And they let it be known. More conflict. Its resolved. It still seems like your drifting apart. They are hardly around at lunch and recess, and sometimes miss out on cles. You know they have problems and exactly what that means but you know this isnt the reason. Your birthday party, firstly Anna can come then Jane can. But then Anna cant and suddenly Jane cant. Instead they spent that afternoon together at Annas house. You barely talk over the next week besides on msn, but really only to Anna. School ends. On facebook they send each other messages about them both being bffls, its sickly and they keep going on about all the fun things they'll get up to, its like their in love. You have to call Jane for some reason, the convo is short. You dont know what to say. You used to hang out alot, she lives near you. You dont wanna ask to do anything and dont think you can stand being around her, she seems to think things are fine. You know she knows somethings different, everyones let them know. You dont want to tell Anna or Jane anything much anymore. You find out that Jane isnt going on the camp anymore with you that was planned just because one of your other friends aren't going on it. Jane had been complaining about for ages. Your now all by yourself on the camp. You think its better this way but were hoping the chance to maybe re enforce your friendship with Jane. Youve havent fought with Anna for 4 years but you and Jane have had a few disagreements in the years you've known her. How would you feel, what would you do? I'm feeling pretty pissed off.