Hi. Frequent palpitations associated with
shortness of breath and headache makes me think of
1) Tachy-arrythmias(abnormal heart rhythm/rate), which can be picked up by ECG during the episode or if required a 24 hour Holter monitoring to record these episodes
2) Palpitations can be a part of normal
pregnancy too because of the increase in the vascular volume
3) Palpitations can also occur due to
anemia especially in pregnancy, moreover there was a history of anemia in the previous pregnancy too
4) Sometimes overdose/ higher doses of synthyroid may also give similar picture, due to
hyperthyroidism or overcorrection
So considering these possibilities, I would like that you check your
hemoglobin, ECG and your thyroid status to know exactly what is causing your palpitations.
Hope i have answered your question. Thank you.