I'm also 12 weeks pregnant and was diagnosed with bleeding in the sac since week 8. Doc gave the same medication and advised the same (don't carry heavy things, no sex).
Since then during the 4 weeks period, as I noticed spotting and also vaginal bleeding, I have went back and doc prescribed progesterone pills with antibiotics as well.
My advise is just to monitor the situation and if you experience bleeding then to quickly call your gynae to check.
So far it has been reassuring, as my ultrasounds have shown a healthy baby. :)
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