Week 4 is when your period should be due. Yours will be strangely absent. This may give you cause to jump about the house madly and fly off the chandeliers, or you may want to sit down with a nice cup of chamomile tea and breathe very deeply. All those hormones rushing through your body will send you mad. Going bonkers is a normal symptom of pregnancy, though, so don’t panic any more than you are already.

This might be the time you want to make sure you’re pregnant and the best way to do that is to get a home pregnancy test kit. This measures how much of the hormone ‘human chorionic gonadotrophin’ is in your urine and the results are 97% accurate. This can be detected on a home pregnancy test stick from the first day you miss your period, although often you may have to wait a little bit longer, until the levels of hormones inside you increase.

Once you have confirmed you are pregnant, brace yourself. If you like the odd drop of wine, alas, your days of alcohol bliss are over. If you are a smoker, it’s also time for cold turkey, and you’ll need to hit the ‘how do I quit smoking’ helpline. These substances can be very harmful to your baby’s development, so if you have any problems with giving them up, talk to your health-care provider, who will be able to help you form a plan of action.

Your baby is only a fifth of a millimetre long this week and you wouldn’t be able to see it without the aid of a magnifying glass. This tiny baby is already starting to take shape, though, and is forming miniscule vital organs in a critical period of its development. It has now changed from being a boring bunch of cells to being a cute little tadpole with a pair of eyes. You’ve got a long way to go yet baby.