Before I had children I always assumed I would have a girl, the thought that I wouldn't didn't really cross my mind. I also knew I wanted a boy but if I had had to choose between the 2 I would have chosen a girl.
I'm lucky in that I always knew I wanted 4 children so although DS 1 and 2 popped out I could always hold onto the hope of 'maybe next time'. However, it did seem that if I was starting with boys I might keep on having them! I had slight GD with my second son but now I am soooooo grateful he came and that I had 2 boys close together. They really do share a special bond.
I swayed with my 3rd pregnancy and was really panicky over it. I didn't find out the gender as I was so scared of GD, I wanted to hold onto hope for as long as possible and I convinced myself it was a boy as a form of self-protection. It didn't seem likely that I would EVER get my girl, how was it possible I would ever get that lucky? I couldn't imagine myself with her, of finally being in the girl section buying clothes, it just seemed like such a distant dream that would never ever be realised. I tried so hard to be happy with having only boys, I love them so much and they aren't at all like I thought boys would be, they are so much more and the interests I have with them aren't at all gender related but I also know there was a part of me that would only be satisfied with a girl.
Well she came, number 3! And it seems as though she was always meant to be here. I'm currently pregnant again to the great shock of almost everyone I know who, despite my having told them from the start I wanted 4, assumed I was only saying that and would stop once I 'got my girl'. I think, if I'd had 3 boys I would have looked seriously into high tech which would have been very expensive and difficult as I'm quite old (37) and would have to travel to a different country for it.
I would say don't give up, if you want more children then you are in a more fortunate place than a lot of women who are looking at the loss of their gender dream due to completing their family for whatever reason. Also, try not to be too sad over DS2, you are giving both your sons a great gift by giving them a brother and remember boys don't have to fit into the stereotype, my boys are both learning musical instruments, love reading and history and animals and are not into sport at all. Your boys will be influenced by your interests, if you're willing to share them with them (I have a friend who loves the theatre and for years refused to take her son because she assumed he wouldn't be interested, would be too naughty and loud etc, she was VERY upset to have him and thought only in terms of extreme boy stereotypes. He's now 11 and they go to the theatre together ALL the time, she admits how wrong she was and although it's horrible of me I'm so very glad the longed for daughter she finally had is an extremely naughty tomboy who refuses to wear dresses, hates sitting still - so no theatre as yet! - and is on her school girls' football team! haha, still makes me laugh).