Daily Calorie Intake?

Before I got pregnant  I was trying to lose 5-10 lbs so I was eating really healthy and only consuming 1200-1500 calories per day. I've kept up with that just because I'm scared if I up my calories to 1800-2000 I'll gain weight like a balooga since my body isn't used to it. 

I am 5'4 and about 130lbs. Currently 11weeks and haven't gained any weight yet. 

I gained 33lbs with my first pregnancy and 30 with my second. I am a lot older now in my 3rd pregnancy and scared to death that baby weight will be a struggle to lose this time.