Should I go to my friends scan? Please help!!!!

Charlotte
Ive been Ttc for 18 months now with no success. My friend is pregnant with her second (got pregnant easily and likes to rub it in) and she has asked me if I can go along to her first scan. I know it will be painful for me to watch because it will just make me sad for myself. I don't know whether to make an excuse and say I'm busy or tell her the truth that it will be too hard for me atm. Or am I just being selfish and should suck it up and go even though it will be hard for me? Please help!!!