My period was13 days late and is very light with minimal cramping. normally very heavy with bad cramps. 4 neg preg tests. miscarriage? or ectopic?

Both unlikely: Home pregnancy tests(HPT) will be positive 7-10 days after conception and definitely by 2 weeks after...So a negative HPT would rule out possibility of miscarriage or ectopic pregnancy. Also, in both these conditions pain and bleeding are usually more than a normal period. Symptoms from an ectopic pregnancy occur 6-8 wks after conception.Your unusual period likely due to temporary hormonal changes