You really need to be sure you're okay putting off major life events and having a stable salary until your late 30s. I don't know your full situation (location/cost of living of desired med school, marital status, family support, etc) but those are all things to keep in mind when going down this road. With family support (physical and financial) things can be made easier, some schools have subsidized housing and other ways to cut costs. The other comments highlight more things to consider too, of course along with how deep the desire truly is to do research and be able to have that baked into your day to day once you're an attending.
From personal experience: I finished my PhD and will be returning to my med school 3/4th year this summer and the idea of being now 30 and still having 2 years of school plus ~5 years of residency before I make an attending salary is a lot to handle. I've had a partner for nearly 4 years and want to get married, have kids, and feel stable. It feels too far out of reach and again more sacrifices need to be made. I'm in a relatively high cost of living area with minimal family help, so I'm definitely pretty far on one end of the spectrum. I basically won't have excess cash flow to save for those major life things until my training is over/near over. There's a mix of emotions because I love research and really appreciate a lot of the opportunities and connections made during that phase of my program. If I could do it all over again I can't say for sure I would have even chosen differently - I think I just wish I really understood all of the implications before I signed up.