If your tubes cut tied burnt one could not become pregnant unless the tubes have rejoined or the pregnancy
has occurred outside uterus-very rare.
Your previous miscarriage
is also doubtful.You may be having delayed periods.6 weeks from the last menstrual period will show positive in conventional pregnancy tests.Your age,number of days since Last Mensrual Period,Anemia
Status,Ingestion of any hormones will have to be taken into consideration