Hi Sampada,

Make sure that you are eligible for in-state tuition while in H4 visa. My understanding is that you need to have at least an I-55 stamp on your passport apart from residing in the state for 6 months to 1 and 1/2 years (depending on the state) before you are eligible for in-state. I have seen that in the websites of several schools ("in-state tuition eligibility").

If you can get in-state at H4, that is great. Don't worry about OPT for now. By the time you graduate, your spouse may have already gotten the green card. If the in-state does not work, then it's worth changing visa to F1.