HELP! :( scared

My period is now 30 days late so I’m going in on Tuesday to have blood work done. I’ve had all negatives on every test but want to make sure. I’m really worried because it’s not something I can afford right now, but seems necessary. Can anyone tell me what it’s like? I have a history of anemia so I’ve never been able to really give blood and when I have had blood taken I have fainted :( the cost and the risk seems awful to me .. but better safe than sorry? can anyone share their experiences? What was it like, is it a lot of blood, how long for results?? I’m really anxious and very young so this is my first time dealing with this kind of experience :( (it was my first time taking pregnancy tests as well) I just want to be prepared