It can take days or weeks till your bridge gets used and you see many connections. If you check you logs there should be a line like this:
Dez 14 20:51:26 host Tor[46906]: Your Tor server's identity key fingerprint is 'nickname fingerprint'
Copy the fingerprint and paste it to this url to check what the bridge authority thinks about your bridge:
https://bridges.torproject.org/status?id=<your-fingerprint>
If it says untested just wait a bit longer, if it says dysfunctional we need some more information to help you, like your operating system and what kind of bridge you tried to set up.