So worried :( I got a very very light bfp yesterday. I was nauseous all day and my boobs have been…

So worried :(

I got a very very light bfp yesterday. I was nauseous all day and my boobs have been hurting for a week now. Woke up today and took another test and the line was only slightly darker. When I woke up I was feeling extremely nauseous. Now I feel like all my symptoms have completely disappeared and I got back from shopping and went to the bathroom and I was spotting a little bit of brown discharge. I should be 4w 2d today but I'm scared I might be losing it. My husband didn't even know I was pregnant because I was going to try to wait till Father's Day to tell him :( anyone else experienced anything like this and still been okay? Now I don't know whether or not I should just go ahead and tell him or wait it out with the hopes that it might still be ok.