Why on earth?

Im just over 6 weeks and why on earth does my brain insist i take a digital test? Is it to keep me at ease? I dont understand, please help me understand. This is pregnancy #7 baby #3 (ive passed my mc time always before 6 weeks) i never felt this way before i had 3 of those mc before my son and only 2 tests were enough. With my daughter i took 4 with this one over 10 tests. Why on earth do we do this?