Is it possible for a ultrasound tech to detect a pregnancy 11 days after you have intercourse, and would you hCG level be over 23, 000 this the case.?

No. Ultrasound will detect pregnancy from about 5 weeks and cannot see it at 11 days post intercourse. A high beta level of 23k suggests you are much further along than 11 days.
HCG level. I only feel medically comfortable addressing a portion of your question. Implantation usually occurs at around 6 to 12 days. Then HCG levels ^. Please see the HCG level charts on this site: http://www.Hcglevelsinearlypregnancy.Com/hcg-levels-chart/. Did the woman become pregnant prior to this?