Just found out Im pregnant!?

I took a HPT on Weds night last week, had blood drawn on Thurs to confirm! Holy heck now what?! They did an ultrasound on Thurs to check for ectopic pregnancy, no sign of yolk sac at all... Went for more blood work on Sunday and again on Tues (yesterday). They have me set for a u/s on Friday this week, and Im nervous that it may be an ectopic... They said my hCG levels keep going up which is really good, and that now they should be able to see the yolk sak on Friday. Has anyone else found out they were prenant and not see the yolk sac on u/s? Im worried. Thanks!