Difficult to say, as it all depends upon what has caused the blood lot.
The commonest cause is from a past and recent ruptured ectopic pregnancy,but you have not mentioned that point, Also pelvic infections in the past may causes a bleeding upset but that would have been excluded before the onset of IVF. It could of course be due to her ovulating.
In the absence of pelvic disease and ectopic pregnancy, I feel that the blood clot will dissolve on it 's own and cause no further problems.