HSG test

So I was scheduled to have an hsg test today that does an X-ray of my uterus and ovaries and had to have my blood drawn on Saturday to make sure I didn't have a current pregnancy. Typically the test is to be done within 10 days of your period, and mine started on the 2nd and ended the 5th. This was my first period after a D&C last month. The doctor called this morning and said I had to reschedule cause my hcg level was an 8.5. I mean my hubby and I have been very active. Could I have gotten pregnant right after my period? The doctor is testing my hcg level again on Thursday.