Opinions?

According to the <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> app that I have always used, my period was due today. I have only been late on my period once in my life. According to this app I am due for my period today but the other one is always more accurate since I have used it for years. So after tonight I will be two days late. Since yesterday (the day before my period was due) I have been very very slightly spotting. I go to the bathroom a lot and there is nothing in my underwear. Sometimes I will take a piece of toilet paper and put it a little up my vagina to see if I can see any blood. Most of the time nothing but sometimes I only see little tiny dots. I’ve been barley spotting like this for almost three days now. Tomorrow I will be two days late. My nipples in the past few weeks about three times have been very sensitive and today one of my boobs started throbbing for a second. Do you think I could be pregnant? I’m really scared to take a test.