Pregnant women metabolize caffeine a lot slower than non pregnant women. In fact, it can take 1.5–3.5 times longer to eliminate caffeine from your body. Hence, it is recommended that pregnant women limit their daily intake of caffeine to less than 200mg per day which is equivalent to:
1 mug of ground coffee;
2 mugs of instant coffee;
2 mugs of tea;
5 cans of coke;
2 cans of energy drink;
4 (50g) bars of plain chocolate; or
8 (50g) bars of milk chocolate (which contains only half the caffeine of plain chocolate).
Do not drink more than 2 cups of fruit, mint or chamomile tea a day. Use teabags rather than loose leaves, and try to make weak tea rather than strong tea.
Also, decaffeinated beverages are also a good idea to consider at this time.