Hi and welcome to the forums!
NFP while breastfeeding is DEFINITELY possible, so don't let anyone tell you otherwise! I was able to do it after my first 2 kids, and now practicing it again after our 3rd!
I'm BF'ing my 3rd child... and we use the sympto-thermal method of NFP. It IS possible to use NFP while breastfeeding, and it can be completely reliable... it's just a little trickier while BF'ing.
My advice is to READ and take additional NFP classes... contact your diocese for local classes, or look into these great resources...
- has a take home course and also may have local teachers in your area...
- has a free online manual
- wonderful book on the sympto-thermal method.
The key to NFP while breastfeeding is to look for the onset of returning fertility... by watching the mucous and cervical position signs. Tracking these religiously can help you determine when the fertile or non-fertile days are and can help find days when you can be intimate. The secondary sign of taking your temperature is helpful in knowing that ovulation has indeed returned... after seeing the fertile mucous and cervical position.
I don't think it's possible to force your body back into normal cycles simply by pumping... some people may have an early return of fertility that way, but others may not... so there's no way to tell for sure.
Look into some local classes and be sure to READ as much as you can on the subject...