You’re certainly not too old for a pregnancy although making babies is more difficult after the age of 40. You will have less than half the chances of conceiving that you had in your 20s and a 50:50 chance of any pregnancy ending in miscarriage. There is also the increased risk of a Down’s syndrome baby. All these problems are thought to be due to the fact that your eggs are getting older and are not of the quality they used to be. There is nothing that medicine can do to turn back the clock.