I plan on majoring in biochemistry and my Math 2 and Chemistry SAT subject scores are already at 750+ so I’m already going to submit those, but should I take the Bio-M test because some places recommend a math and a science but I am not sure at all
No
Chemistry covers you on the science. Unless a college specifically asks for bio (and I am not aware of any that does) you’re fine.
Some schools specifically ask for CHEMISTRY for some programs…but I have yet to see anyone specifically ask for Biology. I think you are good.