Yet another side effect of the huge flood of hormones in your system is an enhanced sense of smell.
Even when not pregnant, psychologist Neil Martin says, "there is a wealth of scientific data showing women's superiority at identifying and detecting odours at even very small concentrations."
It's thought that when we become pregnant we're even more sensitive to smell... and it's not necessarily a good thing.
Smells you liked can suddenly make you gag and feel nauseous. Perfumes, tea and coffee are the worse culprits but even freshly mowed grass can have women retching.
Fortunately this symptom seems to wear off during the second trimester.