I'm instinctively bad with children and infants.

Where are the sanitary napkins?

Human physiology is a three-credit course.

I have bad cramps when I have my period.

Is your menstruation normal?

My period is regular.

I have very heavy periods.

My menstrual cycle is irregular.

I missed a period.

I don't menstruate.

My period is five weeks late.

My last period was two months ago.

Are you having your period?

My period hasn't come.

I'm often told that sleeping right after eating is bad for me, but then I think, isn't it built into our physiology that we get sleepy after eating?

To say that a cat is instinctively averse to water means that it is the cat's natural reaction towards it.

My menstrual cramps have been horrible lately.