Tough question, mainly because everyone is so different and just because someone else got pregnant fast doesn't mean you will - I'm sure I don't have to tell you that, I guess it's the mother in me! I was 34 when my first was born and I unexpectedly ended up quitting work soon after going back when she was about 5 months old. Since I was already home, we decided to try for another baby so we could have them close in age and so we could have the two we wanted and have it out of the way! We started trying slowly when she was around 8 months and I was pregnant two months later, when she was 10 months.
It certainly was trying, being pregnant and having a baby, and she breastfed until she was 14 months and I just couldn't take it any longer - plus, she couldn't fit on my lap very well any longer!
Having my two girls close together was very hard and continued to be (theya re 3 and 4 now) but I wouldn't change a thing. They are the best of friends and enemies from one moment to the next and we're having a wonderful ride! Sorry, I kind of went off on tangents here! I hope something I babbled about helps - best wishes to you!