Is it normal to be sad all the time with low energy when pregnant?

Hindi ko makuhang ilift yung sarili to my usual jolly and happy self. Lagi akong low energy, malungkot, lethargic. Sobrang minsanan lang yung sobrang tawa ko o saya ko. Normal ba ito? Ganito po ba kayo before or similar case? Kasi nagwoworry na ako na baka magkaproblem pagbuo ni baby.