Hi. It means you are trying to conceive.The bleeding you are experiencing may be ovulation bleeding or implantation
bleeding. You have already seen ovulation happening on day 15. But progesterone
levels which are taken on day 21, considering 7 days post ovulation, in your case done after 5 days are showing low values.Level less than 10 is not satisfactory usually. But we don't depend on progesterone levels alone. May be you are having luteal phase defect. Things will be clear after your duedate. I will advise you to consult your dr. and start using progesterone support. Thanks.