Questions about the two week wait?

Brandi-lea • Khaleesi-May Dizney Van Vliet - my precious daughter born on 23.6.15 👶🏼🌸
Im 1dpo and have a few questions- 
​- when implantation occurs, usually how many dpo is it? 
​-if implantation occurs do you always get implantation bleeding? 
​-what is happening to your body after ovulation but before implantation? Has the egg already been fertilised? (If it gets fertilised) 
​- after implantation , how long does it take to start getting hcg in your system? 
​Thank you! X