Dates are wrong surely!!!

Laura • One son 11 years old had Ectopic and lost my baby on 12th Feb2014 ❤️ 2nd ectopic baby lost Nov2014, expecting Feb2017
So according to a pregnancy app my LMP was 5th jan making me 4wks pregnant but my HCG blood level was 48 and apparently 3.5 weeks pregnant. Having cramps and slight light brown discharge...I'm a mess and can't stop crying incase my second bloods on Wednesday show a problem :(