Scared, anxious, and a blubbering mess

My husband and I have been ttc for 3 yrs after 2 MCs and a chemical pregnancy...we finally have a positive result with good hcg levels and progesterone good as well....so why am I so scared? I am 6wks tomorrow and am a blubbering mess...I'm so afraid that something is wrong and that this one isn't going to stay either... I just called my dr and requested to have my hcg levels tested again just to make sure they are going up... am I the only one who feels this way? My husband doesn't understand...he keeps saying "cramps are normal, nausea is normal, all your levels are good what is the problem?"