Brown spotting but lines are getting darker? Reassurance?

Hi ladies, I am 5w1d and have been having a little bit of on and off brown spotting for the past week. But my test lines are getting darker and I still have symptoms. Has this happened to anyone and had a successful pregnancy/birth? I called the advice nurse and all she said was if it's brown it's okay...and to worry if it turns red or is accompanied with painful cramping. But I'm still nervous and looking for reassurance. Thanks in advance!