Thank you for reaching out to us.
If you have been staining non-stop, then this is likely a hormonal IUS. You can check in with your physician to confirm that the device and strings are still properly in place, however staining from the Progesterone secreted by the IUS is fairly common. Though it may abate soon, it also may continue for several months.
Some women report reduced staining with taking Vitamin B1 and Bioflavonoids, doctor permitting. Physicians will sometimes prescribe extra Progesterone to try to reduce staining, with mixed results. You can discuss this with your physician as well.
Otherwise, there is not much to do to control the staining. The question of how to manage relations is complex. On the one hand, we general exercise caution around relations when a woman has non-niddah staining. On the other, the prospect of months without relations is clearly not desirable.
Halachically, when a woman has staining that does not make her niddah, she is permitted to have relations with her husband. Though we usually advise waiting about twenty-four hours between non-niddah staining and relations, as a precaution against a flow beginning during relations, this is not a strict halachic requirement.
In cases of chronic staining, much is left to a woman’s judgment. For example, if you can get a sense of what time of day you are more likely or less likely to stain, or when staining is a clearly non-niddah color (e.g., a light brown with non hint of a reddish tint), or perhaps even wipe externally before relations in a way that will not make you niddah if you find blood, those could all give you cues about when you could more “safely” have relations. For precautions to take when having relations with staining concerns, see here.
Please let us know if we can be of further assistance.