Is mastalgia a symptom of ovulation?
I would explain as follows:
Welcome and thank you for asking on HCM!
Regarding your symptoms, I would explain that they are not related to any serious medical disorder.
You should know that climbing stairs is a more straining physical activity than just walking around the house, so it may lead to shortness of breath, tachycardia and even tiredness or leg pain, especially when you are not a very active person.
I would recommend performing a lot of physical activity in order to stay fit and tolerate better this kind of physical activity.
Other tests to consider would be a complete blood count for chronic anemia, which could lead to this symptomatology.
Regarding the breast soreness, as you refer to be two weeks after your last periods, this may indicate possible ovulation, which is in this period of the menstrual cycle. The hormonal changes that occur during this stage or the menstrual cycle, may lead to breast soreness, and also other changes in your mood.
But this is quite normal and happens in every normal young woman.
So, relax! You have nothing to worry about!
Hope to have been helpful!