The law grants you several rights:
Maternity leave: You are entitled to four months of maternity leave covering the periods before and after delivery, with no less than forty-five days after delivery, provided you submit a medical certificate stating the likely delivery date. The leave is paid, and you may not take it more than three times during your service (art. 54).
During pregnancy: Your daily working hours are reduced by at least one hour from the sixth month, and you cannot be required to work overtime throughout pregnancy and until six months after delivery (art. 54).
Protection from dismissal: You may not be dismissed during maternity leave, nor after returning from it unless the employer proves a legitimate reason (art. 55). You have the right to return to your job or an equivalent one without losing its benefits (art. 55).
Breastfeeding: During the two years following delivery you are entitled — in addition to the rest period — to two breastfeeding breaks of at least half an hour each, which you may combine; they count as working hours with no wage reduction (art. 56).
This is general legal information, not legal advice. For advice on your specific situation, consult a lawyer licensed in Egypt.