This page does not purport to offer legal advice. Beside the fact his is not my field of qualification, the laws governing sexual assault - including in relationships - are so diverse they would need another entire website - however, you'll see some legal resources on sexual assault below.
IPSV is a crime but the decision to go to the police is a deeply personal one. Please don't allow anybody to push you in one direction or another - rather, engage the help of a rape crisis worker to help you decide what is right for you. Don't let anybody tell you it's wrong, or that you have a "responsibility" to stop him from doing it to somebody else - it is not wrong to hold somebody accountable for a crime (even if you loved them), BUT perpetrators are responsible for stopping themselves from raping.
Have as much information as you can so that you remain in control of the process as much as possible.
REPORTING, EVIDENCE AND TESTIFYING
In some countries, laws and legal processes will differ from state to state. In this section are pages pertaining generally to reporting sexual assault. Rape crisis workers should be able to advise you further. Please also browse some of the legal links below.
There is a myth that women who wait to make a report of rape are likely to be lying. This has been unfairly used against women in the courts. Be aware also that marital/partner rape may require a shorter time of reporting than other types of rape/sexual assault (see this article). But there are many reasons why a woman may take time to think about reporting and lay belated charges. In many places, there is no statute of limitations for sexual offenses so, in theory, a victim can report as long after the fact as she likes. The issue of evidence is likely, however, to present difficulties. If it is some time after, trauma and/or the passage of time may have affected your memory - not about the rape itself, but perhaps peripheral details - enough for a defense lawyer to use against you. Do you have anything that may constitute evidence? Photographs of injuries? A hospital visit? Diary entries? Did you tell somebody? Please, if you are making a report, engage as much support as possible..
If you are reporting, I wish you the very best in securing justice. However some women do find that there can be different outcomes. For example, the police may actively talk them out of prosecuting partner rape; the Department of Public Prosecutions may decide not to proceed with the case because they don't want to commit funds to a case that they feel has little chance of succeeding. If the case does get through the filtering process, it may get jurors who hold myth-based beliefs about partner rape, and who do not convict. This is very disheartening, and some women find that it hurts almost as badly as the assaults. It is, indeed, a form of secondary wounding. but it means the system is flawed, not that you weren't raped and don't deserve to be believed. In the end, whether the legal system works for you or not, you can still heal.
If you are reporting, please have the support of friends and/or somebody who works in the field of sexual assault and who can advocate for you. There may also be a Victim Advocate at the courthouse. You need and deserve as much solidarity as possible as you wade into an environment not designed to take your pain into account. For online support, you can also join Pandora's Aquarium, where we have a private forum for rape survivors going through the legal process to discuss their experiences.