Hesitant to TTC...

So this has been on my mind for a while now.  Hubby and I have been TTC since November with no luck! It will be our 3rd and last baby unless we get rich lol! We have 2 daughters now and I am so frightened that I will have a 3rd daughter and my husband will not get the son he longs for. I really want to give him a son 😢. I know this sounds selfish but I cant stop thinking of it!