Mazal tov on your recent marriage!
This appears to be hymenal bleeding, or dam betulim. A kallah becomes niddah from dam betulim the first time the couple completes relations, whether or not she sees blood. On subsequent occasions, hymenal bleeding makes you niddah only if it meets the usual criteria for stains.
Blood found in the toilet does not make you niddah. Blood found on toilet paper could make you niddah if you are Ashkenazi and you wiped yourself immediately after intercourse or of urinating. To avoid becoming niddah from staining, we recommend the following precautions:

Use colored sheets.
After intercourse, both you and your husband should clean yourselves only with colored towels or disposable tissues, and not within 15 seconds after the conclusion of relations.
Wear colored underwear and/or disposable pads or pantiliners.
Wait at least a few seconds (ideally 15 seconds) between urinating and wiping.
Please see our articles on toilet paper, stains, and bleeding after marital relations for more details, and feel free to get back to us with any additional questions.

We also recommend consulting your physician about why you are continuing to experience pain and bleeding after seven months of marriage.
B’hatzlacha!
This response has been updated to reflect the rulings of our current Rabbinic Supervisor, Rav Kenneth Auman, regarding waiting before wiping.