Could I have some advice pleaseeeee

Hi we are trying for number three. We have two healthy girls. I seem to get pregnant fast. This is the first month of trying. I came off the implant last month. Has a period a week after. I'm due on my period next Monday. But today and yesterday have been bleeding/spotting very light pink. My periods are normally very heavy so can't be a period can it? Also from my dates I wouldn't have been due a period till Monday. COULD it be implantation has anyone Experianced this? When can I test? Xx thanks