I have a raised mole on my big toe nail? I think it is a mole, or is a blood clot. But I just noticed it the other day. Is it skin cancer?

Time to see your doc. Any new or suspicious mole should be brought to the attention of your friendly dermatologist.
Get it checked. I'm not sure what you mean by raised. Is it under the toe nail or next to the toe nail.? It could be due to trauma or maybe a mole or even possibly a melanoma. Please have it checked by a dermatologist or plastic surgeon as it may require a biopsy.