trying to conceive 3rd child not going well ?

I got pregnant with my first child at 18, wasn't really trying so I don't know if it was hard to or not. my second was around 24 and we got it on the first try. thought it was going to be easy this time around but it's not. we have been trying for like 5 months and nothing. my cycle is weird so I have no idea when I ovulate i'm temping now but it's hard to remember. I don't know if it's our ages or the fact i'm over weight or what. i'm only 26 and my hubby is 31 ugh it's getting harder, we keep telling ourselves maybe it's just not meant to be right now but it hurts so bad. my best friend is pregnant so that doesn't help. happy for her just gets depressing at times. just got a new kitty so maybe I should just focus on that baby for awhile ?