If you didn't see any error, maybe the installation was successful. Usually you clearly see an error message at the end of the configure or make steps, if any. You can check if libraries and headers have been correctly installed looking at the default location (or the custom one, if you specified --prefix in the configure step). For example, you should have something like
Anyway, try to compile a code which uses the gmp functions and see if it works.
Edit: it should be useful to redirect the standard output and the standard error of the configure/make commands to a file, for further check. You can do this using tee
./configure 2>&1 | tee logfile
make 2>&1 | tee -a logfile
make check 2>&1 | tee -a logfile
then you can grep the logfile for "error" or "warning".