Input needed please.

Dixie
Ok. So I had a MC at 5w3d on May 25, 2016. I normally (as in before pregnancy) start my period EVERY month on the 17th. So my last period was 4/17/16. When I calculate my period/ovulation I use my MC date as my last period. (QUESTION 1: Is this accurate or no?) so (with that info) I am currently 11 dpo and my expected period is due on 7/2/16. I have had symptoms like super nausea, vomitting, "full" feeling in my pubic area, headaches, super fatigue, basically every feeling I had in my previous pregnancy. As soon as I stopped bleeding, we've been TTC again. I heard you are super fertile after MC (QUESTION 2: is that true/personal experiences?) 
Question 3: all of my tests so far have been negative, is there still a possibility of getting a positive test?
Question 4: when should I test if I don't know when AF is due? 
Thank you in advance!