The first place to look is in unposted transactions in Fund Accounting:
Fund Accounting / Maintain Unposted Transactions
and see if they are hanging out there, unposted
The second place to look:
Go to Contributions / Setup / Maintain List of Contribution Funds
Find the Contribution Fund you used for the contributions
Click on the Accounting tab
See which income account you intended them to post to
(if the DB or CR is blank, that may also be a problem)
But, assuming there is an account, it should be in the 4000's.
Goto Fund Accounting / Reports / Account Activity
run an account activity on that 4000's account for all the months
See if anything got posted there.
If not, you may have posted in Contributions, only, which is an option when posting.