Can stress harm my baby? 6 weeks

It's awful and upsetting but recently my partner and I have been arguing frequently, rowing a lot. When I start getting stressed and worked up or shouting, or him shouting at me my tummy starts to ache, and it's like a constant dull ache until I have completely calmed down. It has been like this since I found out I was pregnant We have been arguing a lot. He can't seem to get his head around it and is drinking a lot. he still has not told any of his family and I have told my close family and friends. I think he's in denial. I wanted to give him time to come to terms but it's been over a week since we found out. We talk of living together but I feel like it might be better to stay on my own so I have security in my home where I live with my other 2 daughters, anyway my main question is will all this stress be harming my baby and is this the reason for the period like pain?? Or is it maybe psychological?