Using a condom (properly) is as safe as you ever are.
A condom will protect you against pregnancy the same amount, whatever the time of month.
Although sex during your period poses a higher risk of STD transmission (blood, fluids, that whole fandango), a condom is an effective barrier against STDs.
So...as long as you used the condom properly as you usually do, you have no additional risks. Sex is always a risky activity, but you sound to me like you are being sensible.