If I'm uninsured, how much will it cost for a pregnancy blood test?

I've contacted the three surrounding Planned Parenthood's and they all told me they don't do blood tests. :( How much would you think it would cost if I just went to a doctor and got it done? (Have had missing period for almost a month, 7 hpt have told me negative... either my hormone is too low or I'm just having some period irregularity, which never happens.)