Regex to find part of a code

I am quit new to regular expressions.

In a code looking like

120813.33.45693.4225.34556.med.med.doub.l.1

or 120813.33.45111.778966.34556.def.med.doub.l.1

I have to test that after the 6th point there is effectively "med".

Can someone help in the construction of a Regex to find the text after the 6th point?

Thanks!