Can I buy an EKG machine to keep at my house and do my own ekgs to have my doc interpret?

Yes. You can if you want but there are several problems. 1) you'll have to buy it from underground channels or overseas since they are medical devices regulated by the fda & not meant for consumers, 2) they are very expensive - no insurance will pay for it, 3) someone needs to maintain/calibrate it, 4) someone needs to be trained to use it, apply the leads in the right place, and interpret any issues.