You don't throw up blood when you're pregnant. If you're throwing up blood for any reason you need to go to the hospital ASAP.
How much blood?
How many days now?
Describe the "blackout spells." Do you actually lose conciousness.
If you are vomiting blood, you may have a bleeding ulcer.
If the blood is bright red, it is fresh.
If it is partially digested, it will look like coffee grounds.
Either way, you should go to the Emergency Room, or at least call your family doctor.
Carol