Help ??!


So how does the whole thing about find out when you got pregnant work cause i recently found out i was pregnant myself by in August i had my period twice the first of August to the 4 or so and than had sex on the 6th but than i had major surgery on the 8th and was on a lot of meds and than i had another period on the 19 of August to about the 21 or so and than had sec on the 26 and 1st !! But recently went to hostipal and they told me my blood levels where so low that i was really early but according to this app I’m 5 weeks pregnant but they did a sonogram and could t see nothing on and I’ve done seen two different doctors and now they want me to go see an obgyn and that they will monitor my pregnancy through blood levels like I’m lost and confused as to how far along i really am and when did i convinced??? Does any one else know