Help 4 weeks and scared?

I am 4 weeks pregnet today, last time af came to visit was march 6th. my husband and i have been trying to get pregnet for 6 months. took a few test yesterday 3 plaine old ones and 2 digital ones, i know i know i should space them out a few days but i was happy... anyways. all day today i have had a constant cramping in my lower abd. no bleeding thank god as of yet. it this the sign of a chemical preg? or is it normal, my back hurts to but i also have rumertod arthritis so that could just be that...... has anyone eles had this constint pain, and still have a normal pregnacy. i go to the dr in the am, but i know enough that there is nothing he will be able to do till at lest 8 weeks........ i just so badly want this to be a real pregncy i am not good at sitting around waiting as my head always fills with what if's....... any info , help, simaler feelings i would love to hear...... btw i am 29