Insubordination?

Hi! Hope you can help me. I was made aware that I was just issued an IR(Incident Report) by my boss and he is pursuing my termination. I'm still on sick leave so I don't have all the details but this is what happened:
I called-in sick last saturday and my boss talked to me.He was insisting that i come to work. I explained to him my condition but he said he didn't care and that we had a company physician who could check me up and rush me to the hospital if it was proven that i can not work and so I should report in.I agreed to be there in an hour but I was so sick that I literally can't stand up to prepare. He called me after an hour and I explained to him what happened and that i was even vomiting that I can not report to work. But he insisted again and made me agree to come to work else he would send me over to HR. and so I tried to report to work that day but couldn't. Instead I went to the nearest clinic and got myself checked. there was a missed call on my phone afterwards but I was so tired that I was not able to callback.

So there.I sent him my medical certificate today. Can this be considered insubordination and grounds for my termination?btw, i recieved my regularization a month ago.

hope you can help me

make sure you keep a copy of your med certs. as long as you were really sick for a condition which really kept you from going to work, it should not be considered insubordination.