We are all aware of our personal space - if someone was to come right up to your face you would not be happy, right?
It feels like an intrusion - and it happens to us all.
However, according to a study a pregnant woman's sense of personal space increases during her third trimester.
Scientists from Anglia Ruskin University looked at how a mother's sense of peripersonal space alters when she is pregnant.
The peripersonal space is the space in front of your body - an arm's length is what's people say is their personal space.
The study, published in Scientific Reports looked at 85 pregnant women aged between 21 and 43.
They took part in an audio-tactile reaction time task at 20 weeks, 34 weeks and eight weeks after giving birth.
So why does the personal space expand in the last few weeks of pregnancy?
Lead author Dr. Flavia Cardini said, ''It's the brain's way of ensuring danger is kept at arm's length".
She continued, ''Pregnancy involves massive and rapid changes to the body both externally, as the body suddenly changes shape, and internally, while the fetus is growing.''
Which is quite a reason - pregnant mums are already subconsciously protecting their babies before they're even born.