Nervous

So i've missed two periods.. 3 negative tests and finally had my bloods done. If i am pregnant is it normal to get cramps the time of ly period but NO blood? I searched and it's saying 'if i am' that my insides are stretching that is why i'm cramping? I'm 18 and with my boyfriend of 2 years and we've always been safe. If we are pregnant we've just been caught off guard. But basically i have no symptoms of pregnancy. Other than really sore nipples, feeling sick (not vomiting) and really sore lower back along with some weird discharge. I'm regular with heavy periods. I'd be about 8 weeks along has anyone else experienced this? Also i'm really tired. My nurse said that it is too early to experience nipple pain if i am! But i've read online it can be a symptom! I'm so so nervous and scared. What if it comes back negative.. then what😔