i would NOT get pregnant this soon. you are most likely NOT the most fertile during that 4-6 weeks after; in fact, the risk is higher that you would miscarriage again. heres why:
even though you dont know anything is going on down there in the first weeks, the changes are TREMENDOUS. not only does your body have to completely change after implantation, but it starts to grow and feed the beginnings of a human child. NEVER in the entirety of a persons life do things change as much as in the first few weeks. heart is formed and starts beating, it goes from 2 to 4 to 8 to 16 cells and rapidly! the growth is AMAZING and beyond our comprehension.
as a result, the uterus, body, and general systems down there are kinda "tired" for lack of a better word. its like trees; they lose their leaves in the fall in order to suck the nutrients back into the roots to protect themselves for winter. your uterus, body and all that needs to have the time to bounce back from the preparation and "blooming" that it WAS doing and get back to "normal".
my doctor told me to wait 3 months. not only for the above reasons, but also for emotional ones. you lost a baby. whether or not you saw it, met it, held it, or whatever, it was a baby. you wanted it, you dreamed of it, you were overjoyed. let yourself mourne and emotionally recouperate before trying again. my husband and i didnt go on the pill, but we used condoms during that time (the pill made me nuts anyway) and we just took it slow. we were both terrified of it happening again, because the more times it happens, the higher the chance that something is wrong more than just the miscarriage. my doctor said at 3 miscarriages, they would test both of us for issues that would prevent a pregnancy. and above all we did not want to have to go through that.
i understand your feelings, we had a miscarriage, all we wanted was to get past it and try again. but we will NEVER regret the time we took to emotionally and physically recouperate.
i am very sorry for your loss, and i wish you good luck moving forward. i hope that you do have a successful pregnancy, but i do ask you, from my experience, it is better to wait than risk another miscarriage. its very painful, i know. and its very hard to wait. but its WORTH it.