Welocme to HCM!
On reading your question carefully I can say from my clinical experince that even though your test was negative, it dosent completely rule out
pregnancy. Had I been at your place, I would go for an
ultrasound (USG) pelvis , adnexa and abdomen to rule out pregnancy and other possible causes of your symptoms.
From your symptoms it appears that you may be pregnant ( light beleding in August 1; 28, October 9; then now you have weakness,
nausea,
headaches, lower
back pain, visible veins on breast). In case you are and want to continue with the baby, then do not go for any self medicication for these problems, as almost all medicines are contraindicated in first three months of preganancy. ( they can harm the baby).
Any medicine and further treatment should ideally be given after USG report. Please consult a gynaecologist in person, this will be best for you.
Hope the reply is able to help you
feel free to ask more queries
Dr. Manisha Gopal