I ended my menstrual cycle which came early by a week on the 14th. I was fingered and had sex on 19th. I started to bleed heavily and now period starts?

It is uncommon that. "fingering and having sex" would initiate vaginal bleeding, unless they were uncommonly traumatic. I doubt your bleeding has anything to do with sexual activity. But it is common for hormonal imbalances to cause menstrual irregularities. While I hope you are using condoms for disease protection and possibly pregnancy prevention, use of oral contraceptive pills can often regulate menses. Good luck.