HOW DO I TELL?!?!? WHEN DO I TAKE TEST?!?!?

Hey guys so just a bit of background info,

I was pregnant and had a natural miscarriage at about 5 weeks. The bleeding took about two days (heavy) then followed spotting that lasted the remainder of that week.. it has been exactly three weeks since since this all happened. The week of miscarriage was the week I was supposed to ovulate (on eve app) and this I was supposed to get my period.. obviously due to miscarriage my cycle is expectedly off. Me and my partner immediately started having sex and trying again we’ve had sex often these past three weeks so my question is, when do I take a test?? And is it possible to have conceived already? (Please no comments telling me I shouldn’t be trying straight away, it was a personal decision and I’m aware of the consequences) xxxx