30 weeks pregnant

moms! ask q lang.. Last menstration q po is oct. 11.. anu po ang dpat sundin sa EDD po. 1st tvs ko kasi expected q is July 21. Taz nung nag congenital uts aq, expected nman is July 17. Taz kanina nag pa ultrasound aq ulit July 17 nman daw. EDD at EDC is just the same lang ba? thank you po sa sasagot at sa expert.??