Had a misscarriage 3 weeks ago. best way to get pregnant?

Try again: As long as your hCG level (pregnancy hormone) is down to zero and you had a menses you can start trying again. There is no rule you need to wait a few periods. Miscarriages at 27 happen only 10-15% of the time which means the chance of it happening again are low. I would recommend doing what you did last time and it should lead to pregnancy again. Best of luck to you and your partner.