Mom Is Changing Schedule And Demanding More Money

My (29M) and Ex (30F) have been separated for well over a year now. We have two boys 8 & 6. For the majority of our separation, our schedule has been smooth and we co parent pretty well. We were never married and live in CA. I voluntary give her $850 a month. The supposed schedule is she has them Sunday evening - Thursday morning, and me, Thursday’s after school - Sunday evening.

However, I have had the boys for a good chunk of the week. My work schedule allows me to alternate Mondays, and Wednesdays so I always offer to pick the kids up the night before, take them to school, spend the day with them etc. she would always accept seeing the boys happy to be with me. I do school drop offs, school pick ups, doctor visits, soccer games. I pay for their medical, dental and vision. I am very involved with them. I don’t mind if they stay with me every day. I’m always ready to be with them at a moment’s notice. She recently became pregnant with someone else’s child and decided to cut back her hours at work. She would often text me that she doesn’t feel well and would ask me to watch the kids on days that “aren’t supposed to be with me” Monday, Tuesdays, Wednesdays. She would say that she would make up the time by picking them up on one of my days “Thursdays, Fridays, Saturdays”. She almost never does. She has been very inconsistent these past few months if not year. I always send her the $850 regardless of how much time I have them. She recently decided to take them out of my mom’s day care and start up her own daycare saying that she would no longer need my help with watching them but in turn demands more money. She is now no longer letting me see them on the days that aren’t mine and has threatened to take me to court and get a child support order if I don’t comply with her increased amount. I have been keeping track of the hours I have had them this past year, and every month I have had them more hours than her by over 50-100 hundred hours. Does she have a case if we go to court? I have tons of proof, messages between her and I, and that for the past year they have been with me the majority of the time. My fear is that because of this sudden change, the courts will rule in her favor, and because I do make a decent amount, the amount I would pay would be a lot higher. I have talked to her and offered to give her the $1200 for a certain amount of time while she gets her daycare in order but flat out refuses and wants it permanently. Location: CA