My Twenty Two Year Old Daughter, Healthy Other Than Blood

My twenty two year old daughter, healthy other than blood clots in the lungs is having headaches since starting eloquis. They are thinking the blood clots were cause by birth control and excessive travel. She started the eloquis about two weeks ago. They come in the afternoon and are gone the next day. She says that on a scale of 1 to 10 they are about a 5. Is this something we should be concerned about?