Week's of pregnancy

Noong September 18 nag punta ako lying in check up, bilang nila 35 week's and 2 day's, Nag follow up check up ako noong October 1 , sabi nila 36 weeks and 3 day's nalilito po ako , Due date ko po October 21 , Ilang week's na po ba dapat. ? Tapos ito po yung tracker ko. Tnx and advance