I was recently hospitalized for pulmonary embolism caused by birth control pills. doctors prescribed b12 and blood thinners for 3 months minimum. can i smoke marijuana (in moderation) again once blood clots are dissolved? will it cause another pe?

Blood clots are not the usual consequence of pot. But you should let your doc know for he/she will take that into consideration when prescribing any meds

You describe a recent critical complication and you should not proceed independently to add recreational drugs without a concerted discussion with your treatment team. Furthermore, these days, even cannabinoids can be laced with additives such as Fentanyl.