Nervous about hcg levels

A little history on me....I have 3 healthy children. Got pregnant with our 4th, a girl, in October 2017 and had a miscarriage 2/1 at 17 weeks. Waited to have 1 period at the recommendation of my dr. Had a chemical pregnancy 4/1. I’m worried I’m having another chemical now. The difference this time is that I’ve had definite line darkening on my home pregnancy tests (did not have this last month). And have had some really strong symptoms of breast soreness and nausea. However my beta hcg was only 40 yesterday. I believe that I’m 4 weeks today. I go back for another draw tomorrow but can’t help but think this is another chemical😓