No, it is unlikely for your fallopian tubes to be "untied" after a tummy tuck. During a tummy tuck procedure, usually the organs, including the fallopian tubes, are not exposed and all the surgery is done outside of the abdominal cavity.
A fluid collection beneath the skin or seroma is not terribly uncommon after an abdominoplasty. Typically it will resolve with serial drainage. Sometimes it can look a little pink because the previous drainage may have caused a bit of bleeding. 60 cc is fairly small and may resolve on its own....
At 300lbs, liposuction or a tummy tuck would not be appropiate. As I tell all my patients who are not at their ideal weight, plastic surgery is not for weight loss but more for body contouring. I would encourage to continue to lose weight or visit with a bariatric surgeon.