Under normal labour laws in other countries, you definitely can sue them for terminating you while pregnant and you can make the case that they fired you because you are pregnant. From working abroad for many years, I know that companies dread firing a pregnant woman for those reasons exactly. They think ten times before taking such a decision, because they can see the law suite coming,...

Not sure about the Qatari law though,... It is best to call on a lawyer specialized in these matters,...