I think the breastfeeding def affected your cycles! If you haven't even really tried to conceive #2 yet, I really wouldn't worry!! There's a chance you will get pregnant pretty quickly and all the worrying will be for nothing. My current RE did tell me that at my age (28) and definitely at yours, it shouldn't take longer than 6 months to conceive (assuming you have regular cycles), so that's something to keep in mind. If you hit the 6 month mark- maybe make an appt with an RE to have other things tested.
With my 1st, it took us 9 months. We actually had an initial consult with a doctor that month bc I was getting worried, but I found out 2 weeks after the consult that I was pregnant, so we obviously didn't go through with any of the testing. Now, we have been trying for #2 for about 20 months- so frustrating. The only thing they've found wrong so far is that my progesterone is pretty low (which won't allow for implantation). It's sooo annoying bc it's actually a very easy fix (just take progesterone supplements after ovulation), but we didn't go to a dr until after a yr (since our first took 9 months, we thought maybe it would be the same) and then my first RE didn't even test my progesterone (he figured that since I already had a child, it was probably normal). So, we just found out about this abt a month ago with my new RE. Even though we could try naturally with progesterone support, we decided to try IVF this month since I have off in the summer, it is covered by our insurance, and bc of my low AMH #.
Anyway, try to think positive!! Who knows, you may be successful on your first try!