.This Is Prince.. I'm Having One Doubt...my Doctor Advised Wife

.This is Prince.. I'm having one doubt...my doctor advised wife to inject fertigyn hp 5000 for pregnancy and injected today (28.01.2017) at 11am. Also doctor advised me to intercourse daily for 3days(28.01.2017 to 30.01.2017) and asked my wife for scan on 31.01.2017. My question is as follows
1. When is the right time for intercourse for pregnancy
2. While scanning on 31.01.2017 is doctor know about conceiving..
3. During scan doctor found that ET is in 5m...whether 5m ET is enough to conceive? What is the normal side for ET