Went to the er 4 days ago due to vaginal bleeding, while 6 wks preg (similar to day 2 of period) & a sharp pain in my vagina. no more pain but still light bleeding. hcg was 425 4 days ago. should i return for hcg follow up or wait 1 week for ob appt?

Take either option. An HCG of 425 is extremely low for a six-week pregnancy so if you are sure of your dates rechecking your level though necessary is mostly a formality. You'll have an answer quicker but if you need any sort of procedure, like a D & C you'll still have to wait for the obstetric appointment. However, 425 is normal for 4 weeks. Thats why the recheck. So, if that's possible, go now.