How can I check if my phone supports GLONASS, WAAS and EGNOS? I know my phone has a GPS receiver, and it is able to find my location using that.

But does it also use the GLONASS satellites? 
And can it use WAAS or EGNOS, to improve the accuracy of the position?

It their any way to test if my phone is using these?
If you can see the NMEA data , may be from Android APP (available in plenty) , the Prefix would say what GNSS system , its supporting . Like GP Prefix stands for GPS. GLONASS should be GL and Galelio would be GA. But there are some NMEA Sentences which combine  more than one GNSS System and use a different prefix. Better to understand NMEA Format . 

$GPRMC,162254.00,A,3723.02837,N,12159.39853,W,0.820,188.36,110706,,,A*74
$GPVTG,188.36,T,,M,0.820,N,1.519,K,A*3F
$GPGGA,162254.00,3723.02837,N,12159.39853,W,1,03,2.36,525.6,M,-25.6,M,,*65
$GPGSA,A,2,25,01,22,,,,,,,,,,2.56,2.36,1.00*02