Just do it whenever you're comfortable and when theres no pain. I had sex 2 or 3 weeks after vaginally giving birth to my first child and got pregnant with my second. i've never heard about 'having problems conceiving if we have sex during confinement'. but i never believe in folklores.
I would only do after confinement. Because if you have vaginal stitches it will heal at least about two to three weeks.