Most female dogs come into season for the first time between 6 and 12 months, although some larger breeds delay until as late as 2 years. Like most mammals, the age that a bitch first comes into season is mostly a function of her current body weight as a proportion of her body weight when fully mature. They then experience estrus about every seven months until old age. Female dogs do not experience menopause, although their cycles will become irregular and fertility becomes unpredictable as they become older. Dogs over around 7 or 8 years are usually considered no longer appropriate for breeding, but can still remain fertile.
A woman can get pregnant at any time but the best time is about 12 days after menstruation has finished up until it starts again
The average menstrual cycle lasts 28 days, from the start of menstruation to the start of the next menstruation. The "bleeding phase" typically lasts 5-7 days.
It may last for one week or so..
Usually up to two weeks.
None, some days are more likely than others but nona are safe.
Menstruation typically occurs about 14 days after ovulation in a regular menstrual cycle. This phase between ovulation and the start of menstruation is known as the luteal phase, which generally lasts between 11 to 16 days. If fertilization does not occur, hormonal changes lead to the shedding of the uterine lining, resulting in menstruation.
If you buy monthly - 30 days, 3 months - 90 days etc.
30
There's not necessarily a problem. Although menstruation typically lasts between 5-6 days, many women's menstrual phase is a lot shorter than this - if you are in your pre-teens or teens especially periods may be a little erratic so sometimes be shorter or longer than normal.
Typically menstruation lasts 5-7 days, but a little longer or a little shorter is normal too. During a regular cycle you should only bleed during menstruation, but it is possible to experience a few days bleeding mid-cycle too.
premenstrual syndrome: a syndrome that occurs in many women from 2 to 14 days before the onset of menstruation
You can never be to careful so you should always use the pill or a condom