How soon to IVF?

We had started seeing a fertility specialist after our third consecutive miscarriage. Did all the bld work and HSG testing. A couple days before we were to meet with the specialist again we found out we were pregnant. We meet with him and he stated our next steps were IVF and then I had to tell him I was pregnant again. This one ended up being non-viable as well. I can’t seem to get past a 4-6 weeks. How long after a miscarriage did you start your IVF process? I know it’s different for everyone but just hoping to get a general idea. I go for another round of bld work Wednesday to make sure my levels gone.