Hi, and thanks for your question
While HIV can technically be passed through breastmilk, we typically see this from a mother who has HIV to an infant when the baby actually ingests breastmilk during regular breastfeeding multiple times per day. If the breastmilk only came in contact with your skin, then there would not be a risk. And as you’ve pointed out, the HIV status of your partner is unknown.
The 4th Generation HIV antibody test is the standard test used in Canada and the results are accurate at 12 weeks after exposure, as someone who has acquired HIV will have detectable antibodies at this time. Since you’ve tested several times beyond the 12-week mark and your results were all negative, this means that you do not have HIV.
The symptoms you are describing are not specific to HIV and could be contributed to many things including common viruses and infections of the mouth. If you are concerned about your symptoms, I would recommend visiting a doctor for further assessment beyond HIV testing.
Let us know if this does not answer your question or if you have any more questions or concerns.