Long ago, my sons father and I agreed that he would pay $50 a month in child support. I've been receiving this amount for the last 16 years without any additional financial assistance from my him. I now regret never having this amount modified. My son will turn 18 in August. Is there anything I can do to get any "back pay" or am I too late?

Where? My concern is that you reached an agreement with him and now you are trying to get around it.

We live in California. True, we made this agreement when my son was a toddler because he would stay with his dad 3 nights a week. When my son started pre-school he only saw his dad every other weekend. I could have and should have gone to the county and asked them to review the order but sadly I never did. It's my own fault for waiting but I just now worked up the courage to fight for me & my son.

You made an agreement with the father of your child. 18 years have passed. Now that he's paid (apparently faithfully) an amount you agreed upon (and a Court could have ordered less) you have decided to "fight for ... your son."

How are you fighting for yourself? The father owes you no support.

I personally think this is unethical. You had an agreement, a contract. He followed the terms. Now you've changed your mind and want MORE money for the past 18 years.

Yes, you should have gone to Court many years ago. I don't think you're going to win this one.