Reference no: EM133462999

Scenario:

Amber had celebrated her eighteenth birthday while in Sydney. Although the trip had been exciting, she had felt sick the whole time, and the flu-like feeling still hadn't subsided. She was a little concerned, but attributed it mostly to nerves and lack of sleep. That night as she lay in bed reading, she was unable to concentrate and her mind drifted, thinking about the recent break-up with Brandon. Amber was reminiscing about the last night she spent with Brandon.... I wonder if mum knows she's pregnant ... I've been here nine weeks; she's got to know soon. It seems like only yesterday I was a tiny blastocyst, traveling down her fallopian tube and implanting into her uterine wall. I'm about half an inch long now, and I weigh a little over a gram. I'm growing like crazy! My ears, nose, mouth, and limb regions are popping out and the cerebral hemispheres of my brain are well defined. My hindbrain, which will regulate my heart, breathing, and muscle contractions, is really starting to develop. So is my pituitary gland, which will regulate the rest of my glands once they develop. Although my eyes have formed, the eyelids are still fused so I can't blink yet. My heart has been beating for a few weeks and is now separating into four chambers. My diaphragm, stomach, kidneys, and intestines are developing too. Although my gonads have formed, they still haven't differentiated into either testes or ovaries, but I know genetics has destined me to be a beautiful, healthy girl. I'm receiving my nourishment through the yolk sac now, but in about two to three weeks, my mum's placenta will take over completely. I feel so sorry for her right now. The high levels of HCG (human chorionic gonadotropin) and progesterone circulating through her blood are making her nauseous, but I know she'll look past that once she knows I'm in here. Even though these placental hormones are making her feel bad, I need them so her body will not reject me and instead allow me to continue developing. Mum doesn't know it, but the folic acid in her daily multivitamin is helping my nervous system develop normally and her calcium is helping my bones grow strong. I hope mum will be happy when she finds out I'm here. Now when mum takes that pregnancy test, she'll finally know why she's not feeling her best. Even though her menstrual cycle is very irregular, she did become pregnant. Mum didn't know that she ovulated the day of graduation, and there was a perfect egg waiting to be fertilised. Fertilisation is most likely to occur from 72 hours before ovulation to 36 hours after. Since sperm can survive in the female reproductive tract for about 48 hours, fertilisation did occur the night of mum's graduation to form a zygote and then eventually an embryo, me. Luckily for me, mum's timing was PERFECT. I'm finally able to move spontaneously, but mum can't feel this yet. But she knows something's going on. Her placenta where our blood supplies practically mix together is giving me nutrients and antibodies to fight off disease until I can develop my own immune system. Mum's natural killer cell activity in her blood is lower now. When I was first conceived, her body released an immunosuppressant protein called early pregnancy factor (EPF) so that I wouldn't be considered an antigen or foreign body.

1. What are the physical changes that occurred during Amber's normal menstrual cycle to increase the chance of becoming pregnant?

2. Apparently Amber did not use any form of birth control. If she had used the oral contraceptive pill, how would the oestrogen and progesterone be affected to prevent a pregnancy?