Welcome to the forum. Yes, during pregnancy
many women get these dark spots on their face. These are called melasma
which are really stubborn. Since it is almost three years since you have them it may take time to go away. These marks are also caused due to oral-contraceptive
pills that most women use to plan their family. ( it is a side effect that effects some women not all )
I will suggest you not to take these pills and use barrier methods
to avoid pregnancy.
You should take plenty of water, juice and soups to keep yourself well hydrated. Include dietary supplements or take food and fruits rich in vitamin B, C, E. Reduce the tea and coffee intake. You can apply natural papaya ( yellow) pulp as a face mask for 20 minutes regularly, it is very effective. You can also apply lemon juice which is a bleaching agent.
Do not use strong cosmetics. Laser therapy
shows very good results. You can consult a dermatologist
who is an expert in giving laser therapy. First check whether your sensitive skin can take the therapy. If yes, go for it and you will get the result. It can help you look very fair. Have a good day, take care.