The enlarged version of a girl's tits while she is premenstrual and/or menstrual. Generally happens about a week to 4 days before starting her flow and may last throughout the week of her period, as well. Usually adds a half a cup size or even a full cup size to the female's nonmenstrual rack.
I thought I found a woman with bodacious tits, but it turned out they were only temporary period boobs. Bummer.