Hallow Dear, I appreciate your concern. However, you have once proved that you can produce a healthy child. So you do have good chances of doing it again. Just get rid of the stress. I would advise you first to concentrate on the health of your husband before you attempt for the pregnancy. Once he is healthy, you can go for it. I would not call variation of 4 days in the menstrual cycle as irregularity. One cycle coming only after 15 days may be ignored and next cycle may be expected as per the regularity. If it still does not do so repeatedly, then you may have to report to the Gynaecologist for check up and advice. The stress also is known to cause irregularity in menses. After the regular menses, you may monitor your egg formation. Usually, the eggs are formed 14 days before the menses. On this day, there is profuse vaginal discharge also. If you take the discharge on your fingers and try to pull between two fingers, it forms a good long thread (spinbarkeit). On this day, usually there is rise in body temperature by half degree Fahrenheit after initial fall by half degree. The egg formation also can be confirmed by serial ultrasonography, usually from 9th day of menses. Try to utilize the day of egg formation. It will give you good results. The egg has got life of 24 hours while the sperms are active for 72 hours. Hence, a period of week around the day of egg formation is considered as Fertile period. This information also may be useful to you while planning your marital relations. I hope you are happy about the information and knowledge and will give me a good news of your pregnancy soon. Wish you the best luck.