Implantation bleeding or something else?

Hi, I am 29 yrs old,my last menstrual cycle was started Oct. 2nd or 3rd and ended around the 6th or 7th( I do not track them). I am regular, seems to come about every 4 or 4 1/2 weeks. My husband and I had intercourse several times between Oct. 14th and 18th. On Oct. 20 I woke up to discover it seemed I had started my period 2 weeks early. My question is could this be heavy implantation bleeding or even an early miscarriage? Or is there some other explanation for this?

[nickieb85]

There are alot of reasons for early periods (messed up ovulation) but usually most women don't even notice implantation bleeding (30%) Was it like a regular period? Usually implantation is barely noticeable. Take a test when you are supposed to get your period or see a doctor for a blood test!