I Took Meprate For7 Days.after 7 More Days I Don't

I took meprate for7 days.after 7 more days i don't hv period.i started meprate on 12 th day of my missed period n after doing a domestic preg colour tesr.i hv problems regarding delayed cyle.i had similar experience last time.that time i had a missed abortion.23rd july was my last period date,6 weeks after the miscarriage.how will i understand whether i hv conceived or nt?if the beta hcg shows negative once more like it did last time?