Am due for AF today, so far it has not started yet , Friday or Saturday(can't remember which now) I had light pink/red spotting , thought it was my period starting but it never did get Any worse it just stopped. Have taken tests the last week and all are negative. But haven't taken any now that my period is actually due...my quotation is ..do you think it's possible I could still be pregnant or probably not? & do you think I should test again?& when?

Thanks