TTC after stillborn birth

Alivia • I’m 23 and married to my love, I have a 3 yr old girl and a angel baby boy was born December 3rd @ 37 weeks n was stillborn.. our rainbow 🌈 baby Boy #3 Tobias is finally here

I’m new to this app but I delivered my baby boy at 37 weeks and unfortunately he was still born, n I’m wanting to get pregnant ASAP.. I’m ovulating today but we tried last Tuesday and I was 4 weeks postpartum and I’m 5 weeks and 3 days now so how soon Can I take a pregnancy test? Just need advice