Hello,
Welcome to hcm,

Edema during third trimester of pregnancy is common. As your blood pressure is normal there is no need to worry. Sleep in left lateral position which will decrease pressure on your inferior venacava so that edema will be reduced. Continue elevation of your feet. Get Your blood pressure checked regularly.

Thank you

hi..
thanks for posting in HCM.
i understand your concern.
Swelling of feet (pedal edema) and hands in pregnancy can be physiological (not dangerous) or pathological (dangerous - underlying conditions like preeclamsia). before coming to a tentative diagnosis, i would need some more details regarding your history like:
1) is the swelling present in both the legs? (mostly physiological)
2) have you tried elevating feet while sleeping? if so, is the swelling getting reduced? ( if yes, mostly physiological)
3) hows the BP? ( if BP is normal, mostly physiological but in some cases of underlying disorders, BP may not be high)
4) along with headache, do you have any other problems like nausea, BLURRING OF VISION OR BLEEDING ? (if you have any of these symptoms, it would mean you are landing in HELLP SYNDROME).
HELLP syndrome is a life threatening pregnancy complication. it can be diagnosed with physical symptoms like HEADACHE, NAUSEA, SWELLING of body, VISION PROBLEM, BLEEDING from any of your openings. I understand this all seems scary and your headache might be just due to dehydration, but i would suggest you to immediately consult your obstetrician if you are experiencing any of the above symptoms. Urine protein levels, platelet count and liver enzyme levels can confirm the diagnosis.
it is very much treatable if diagnosed early. hope my answer helped. please write back if you have more doubts. have a good health and healthy baby. thank you.