I am so sorry to hear of you partner's passing away. This must be a very hard time for you. I agree with the post above, you can try to think of how your partner is still with you both in spirit and in your baby that you created together!
About the stress, you are most likely going to be okay and not cause a problem to your baby. Try not to stress about stressing, on top of it, easier said than done. Although this does not compare to your experience, I experienced some very intense family stress over the holidays. I was very worried I could do harm to the baby just through the stress (anger, loss of sleep and appitie. My aunt was very supportive and told me women go through all kinds of things during pregnancy (unfortunately), and do okay. Our bodies must just be made to handle it somehow.
Make sure you are eating well and resting, all the time if you can. For me high stress makes me not want to eat, and if this happens to you it's important you try to eat. Even milkshakes, smoothies, any comfort food.
Also try to be with people you love, and use the help of a counselor (I first wrote consoler, that must be where the word comes from) for the additional support. If you need help finding one in your area, let me know and I can look online.
Take care of yourself! You will get through this!
I know sympathy is the last thing you need but I am sorry to hear I am also going through alot of stress right now there is a possibility that my mom has cancer, she is not doing well at all and I am having alot of issues with my child's father I am 9weeks pregnant I have these terrible headaches, I am worried that it might cause harm to the baby but girl look at it like this God is still God He gave you a child from your partner which is awesome when you look at that child you will always remember the man you love alot of lady's never got that opportunity to have something so precious from their love ones so cut out the stress and God will do the rest.
I am so sorry for the loss of your partner this must be an incredibly difficult time for you. The only thing that I can say is to do your best to stay calm which is by no means easy. Are you reaching out to a grief counselor or someone who may be able to help you through this? The members on this site are very supportive and we will try and help , but you really need some one who can be physically there when you need a hug and a shoulder to cry on.