Your both questions are different having different scope. Sex during pregnancy after 14 weeks of pregnancy is allowable. Usually, women physically find it difficult to have sex after 7 months of pregnancy. However, if you can do it, no problem. However, if you have noticed bleeding after each sex now, I would advice you now to observe sexual abstinence since the penis seems to hurt some tissue inside. Now let us come to the placental aging. Placenta is an organ of the baby inside the uterus which is attached to the uterus and is supplying the baby required oxygen, nutrition, hormones, etc. and taking away the unwanted blood gases and chemicals through mothers circulation. As the pregnancy starts approaching its term, the placenta starts getting aged. It means, the blood supply of the placenta from the mother starts diminishing and ultimately and gradually placental tissue starts dying slowly. Usually this process in noted after 37 weeks of pregnancy. Now that doctor has warned you about placental aging, you have to keep a watch on the baby s well being. The best way for you is to note baby s movements. Usually the baby moves once an hour. Please note these movements and mark them on a sheet of paper. Everyday, measure the foetal movements for continuous 12 fours. If in these 12 hours, the baby moves for minimum 10 times, it is healthy. If this movement count diminishes, please report to your obstetrician immediately. Rest of the things like baby s heart sounds and alertness will be seen by the doctor. The doctor may ask for Non stress test and ultrasonography report with Manning s score to find how safe is the baby inside the uterus. Please keep on visiting your obstetrician now onwards weekly. Hope you have got the answers. If anything further required, please ask me.