I'm afraid of a chemical pregnancy ..😏

Of course me and my anxiety worry about every possible thing that could go wrong.. I got my bfp 2 days ago I'm very excited the line is faint but defiantly there I retested today and yesturday and it still looks the same I'm due for my period on Monday and I'm just praying nothing goes wrongΒ 
If the test stays the same color for 3 days does that still mean it's a definate positive? I'm just scared because it didn't get any darker ..Β