2 weeks pregnant: Changes for mum and baby

Changes for mum

Luteinising hormone and other hormonal changes

Your body has already begun producing luteinising hormone, which is responsible for the final maturation of a single egg, housed in the single ovarian follicle which has become dominant. The dominant follicle is the one which accesses more blood and produces more oestrogen than the thousands of other follicles in the ovaries. Luteinising hormone production begins when the dominant follicle starts producing oestrogen, usually in week 1, 5-7 days from the start of your last menstrual bleeding.

Your egg must fully mature before ovulation (the release of your egg from your ovaries to your fallopian tubes). Luteinising hormone facilitates the maturation process. When the egg is ready for release, a surge in the level of luteinising hormone causes the follicle to rupture and release the egg. Ovulation occurs 24-36 hours after the surge in luteinising hormone.

Changes in your womb

Your womb is also undergoing changes when you are two weeks pregnant. Particularly important is the increase in secretion of a glycogen-rich substance, which prepares your endometrium (the lining of your womb) to allow the egg to implant, should it become fertilised. The increase in secretions in the endometrium creates the ideal environment for the fertilised egg to implant and obtain the nutrients it requires to continue its growth until the placenta forms (in week 5).

Basal body temperature changes

At around the time of ovulation you will experience a slight increase in body temperature (0.2-0.3°C), as luteinising hormone surges. If you want to track your temperature to try and detect this change, you’ll need to measure your temperature before getting out of bed each morning in the lead up to ovulation. As any form of physical activity affects your body temperature, it’s necessary to measure first thing in the morning before physical activity starts.

Cervical mucus changes

Your changing hormone profile also causes the mucus from your cervix (the entrance to your womb) to change texture; it becomes thinner and more stretchy. It is possible to detect changes in your cervical mucus if you examine it every day, however the process is fairly subjective. If you don’t notice any change, it does not necessarily mean that you haven’t ovulated. It’s also quite possible that you simply missed the textural changes in your cervical mucus.

Conception, should it occur, typically does so within 24 hours of changes to your body temperature and cervical mucus texture. Your egg is capable of being fertilised for 12 hours before, and 24 hours after ovulation.

Changes for baby

Assuming ovulation occurs on day 14, the last day of week two, fertilisation does not occur and your baby does not start growing until the beginning of week 3. Once released from the ovarian follicle, the mature egg, which is ripe for fertilisation by your partner’s sperm, begins travelling from your ovary to your fallopian tube (you have two of each, but only one ovary will produce a mature egg each menstrual cycle).

The egg is microscopic and cannot be seen with the naked eye. It measures just 1/10 of 1mm.

References

More information on the 2^nd week of pregnancy

For more information on the second week of pregnancy, see 2 weeks pregnant.

For more information about preparing your body for pregnancy with healthy eating and exercise, see How to get pregnant and preconception health information this week.

For more information about how to improve the chances of getting your partner pregnant, see Men’s health and how to improve male fertility this week.

For more information about conception and the myths surrounding it, see Misconceptions about conception this week.

For more information about the key points on the second week of pregnancy, see Key points this week.