Louisiana Child Support

[tired5047]

Here's my situation, need advise.  I have three children, ages 18, 16, and 12 from a woman, never married. The 18 year old is out of high school. no college.  Approximately 10 years ago, me and baby mama signed a notorized agreement of $500 per month child support, however, the children would live with me during the summer months (approximately 2 1/2 months out of the year).  Over the course of the 10 years, my eldest son has lived with me 5 years, my youngest son 1 year as he suffers from a developmental delay and finding a school for him in my area was difficult, and my daughter 3 years.  As a result of this, we agreed that the payment of child support would be $400 about 5 years ago when the kids started living with me, and I have consistantly paid child support for these 10 years.  Baby mama finds out that I am about to get married in a year and now says she is going to put me on child support through the courts and that I won't be able to see my children next summer. I make about $40,000/yr, she makes about $10/hr. Will the court require me to pay more than I have been paying, or is the fact that we have a signed agreement sufficient enough. I have even considered calling child support on myself to begin the process. Please advise.