PREGNANT? Severely painful back aches, cold thighs, and cramps..

Hi, i was expecting my period to come on the 10th july, but i just had a light brown stain, i was worried so i tried the upt and it came back negative. The next day my period still didn't come but i had severe back aches and my thighs were freezing cold, had cramps n gosh I thought i was going through pms. So after a whole day from morning to night i finally took pain killers. On the 12th i was feeling much better but my period still wasn't here.. so i took another test n it was positive!! I was thrilled but the line was not dark enough. The question is, has anyone experienced the severe pain b4 knowing your pregnant? Is it normal or its a false alarm? I visited the doctor the moment i knew i was positive but she said to wait for another week for a clearer proper scan if theres anything wrong.. Is the pain normal? Im worried and curious..