Don't feel too old at 30. I am that age and waiting till I finish 3 yr IM residency to start having kids at 33. Depends on how many you want, I want 2 and starting then is totally fine. 35 is sort of a worrying year. Someone close to me in medicine didn't start family until attending at 40!! I don't suggest you wait until then necessarily, but you get what I mean. She loves that she is an older mom she feels she is a much better and devoted mom because of having more life experience, knowing who she is, and is at a place with career to focus more on being a great mom. She loves it.
Focus on the couples match, most important is doing what career you love, you'll do that long after kids leave home.
With couples match, balance doing the career you want, where you can get together for your relationship to thrive. As the poster said above, great things to think about as far as programs. As IMG options of cush residencies may be hard and desirable cities may be hard. You could do a year long distance for his prelim year if he gets derm.
If he does derm and you want endo, endo is less competitive fellowship (all fellowships are competitive) but you could time a baby for later in IM residency, with him being done with derm and you starting fellowship, getting pregnant his last year residency would be a great time. He would be attending when born and at least one parent with a good amount of time free, and fellowship can be hard but I think endo fellowship not as bad as IM residency or other susbspecialties.
Family isn't a bad back up, cam be more family friendly especially at family friendly residencies.
I think you guys could realistically go after you top career choices, and put off pregnancy for mid 30s. A lot of people do this, and have the best of both worlds career and family.
Don't be afraid to follow your dreams, put in the time, put off kids until you've got some residency years behind you, take it as it comes.
If your partner gets to attending before you, and you have a baby, depending where you are and cost of living and his job, if you live simply frugally, depending on loans, could afford childcare, or depending on your other family member's careers, I know one couple's mom was able to leave job and secretary, and her husband, for like a year to come help with childcare, and the couple was able to afford helping their parents financially so the gramma could do that. Grampa was able to make do at his job and the house on his own for that time without Gramma with the financial help. It was a win-win for everyone, baby with Gramma, the couple, even helping financially saved money on childcare but baby was with family, and Grampa did OK on his own with financial help and visits from wife. It was a sacrifice on Gramma and Grampa's part for a short time before everything was back to status quo.
Just ideas on how people make it work, and me saying hey, you can put things off a little. Probably not until end of fellowship but later in residency.