Assuming you are within California, the California medical marijuana laws read as such:
"Under Prop. 215, patients are entitled to whatever amount of marijuana is necessary for their personal medical use. However, patients can be arrested if they exceed reasonable amounts and they can be cited or fined for exceeding local laws. Under MMRSA, which took effect Jan. 1, 2016, qualified patients can cultivate up to 100 square feet for personal medical use, and primary caregivers with five or fewer patients are allowed up to 500 square feet. Exemption under this section does not prevent a local government from further restricting or banning the cultivation of medical cannabis."
Your are also subject to local laws, how much the dispensary allows you to purchase and unfortunately, the law does not protect you from a possible raid. For instance the local police could deem you to have an excessive amount. If growing for personal use I would error on the side of caution.
This is my opinion based on research and I am not an expert in marijuana laws. I hope this helps!
Im not sure if the SB420 guidelines have changed, but it used to state that you are allowed 6 mature plants and 12 immature. meaning 12 clones would be your limit under SB420. If Pamelas response is correct and overrides SB420, then thats pretty good news because you can get away with a lot more plants in a 100 sqft