"is there any way of detecting pulse dial?"

Of course there IS!!
Surely this must be blindingly obvious!!???
If there were no way to detect pulse dial, how on earth would pulse dialling ever work? How on earth would automatic telephone systems have been possible before the invention of DTMF??!!!
As I've said to you before, you don't even need electronics - let alone microcontrollers - to do pulse dialling; you can do it all entirely electromechanically - which is precisely how it all started over 100 years ago!!

Do you understand how pulse (or "loop disconnect") dialling works?
Have you stopped to think what actually happens when you turn the dial on a "real" telephone?
Well, it's like this:

When you release the dial, it travels back to its "rest" position sending a series of pulses as it goes:
1 pulse to dial '1';
2 pulses to dial '2';
3 pulses to dial '3';
etc, etc
10 pulses to dial '0' (note where '0' appears on the dial)

So, back to your question, detecting pulse dialling just requires
1. Pulse detection;
2. Counting the detected pulses.

You can find the specifications for Loop-Disconnect ("Pulse") dialling on the BT (British Telecom) network here: http://www.sinet.bt.com/351v4p1.pdf - see section 4.2

Don't forget that LD dialling could be generated mechanically - so your microcontroller will need to debounce the signal (search this form for "debounce")