When is the best time to do a self breast check?

I'm seeing mixed answers on google. One source says a week after your period, but it doesn't specify if that is one week after the start of it or the last day of menstruation, Another says 3-5 days after start of period. Another says 10 days after the start of your period. Another says 2 weeks after your period?

Update: I'm a hypochondriac, so checking every single day is too daunting for me. They say once a month is good enough. I was just trying to find out the best time because I know close to or during menstruation, breasts can swell up.