there are 6 possible combinations of each pocket pair. in terms of pocket pairs, offsuit hands, and suited hands, there are 169 total hands (ie poker tracker style). if you want to know the number of combinations including both rank and suit, i first choose one card from 52 and then choose one card from the 51 remaining and divide by two.

52C1 * 51C1 = 52 * 51 = 2652 and then you divide by 2 giving 1326.

the reason you divide by two is because 8c7h == 7h8c. ie the ordering of the cards can be chosen differently but it does not matter.