You made more money, it's win win either way. If you pass into the next bracket, you're only paying a higher rate on the amount that surpassed that threshold. So it won't make a massive difference unless you've been withholding too little or contributing too little.
If your employer offers shares, you may also be able to dump some of those shares into RRSP (too late now though). That's what I did this year to use up more of my available contribution headroom.
I buy RRSPs, but what I normally do is call my tax person and give her the numbers she needs and she lets me know if I need to buy more. I did that but I did not have my T4 yet, my company usually only sends it out at the very last minute and RRSP deadline was a week ago. The numbers I gave her were lower than what my T4 says so I'm scared I may have actually had to buy more RRSPs but now it's too late.
I'm still waiting for a receipt from the church for donations. I'm hoping that will help me. I did not count that when we were calculating over the phone.
Problem with being at the edge of a tax bracket is you end up making less money and also end up owing instead of getting a return because you were taxed less throughout the year. I'll see how it works out this year though. What I may do is either get the company to take out more taxes or buy more RRSPs throughout the year. I normally use my shares but I had lot of expenses this year such as my LASIK surgery that I needed to pay off.
I just hope I don't end up owing like a grand or something.