Sorry for the delay. For your info, the CPS/ PPS(NI) usually review cases for decision on whether to charge (or not) after the police investigation has been completed (although there are many exceptions). A two-part test is applied, an evidential test and then a public-interest test. A case which does not pass the evidential stage must not proceed, no matter how serious or sensitive it may be.
In its most basic format, the evidential test requires that the CPS must be satisfied there is sufficient (admissible) evidence to provide a realistic prospect of conviction to be able to 'charge' an accused. (They must consider other issues such as what the defence case is/may be, and how it is likely to affect the prospects of a realistic conviction).
If an evidential test is passed for any offence classed as 'serious crime' then I'd suggest prosecution is required in the public interest. (for this this type of offence i.e parties known to each other = 'serious crime', parties unknown to each other = 'major crime'). However, as mentioned, cases which do not pass the evidential test must not proceed.
For many reasons, rape offences classed as 'serious crime', are extremely difficult cases for police/CPS, mainly due to lack of solid admissible evidence and often resulting in there not enough to meet the evidential stage of the Code test.
"Can I ask is it a good indication that I have not been charged....". Simply put, Yes, (obviously its better than being charged), but bear in mind unless you were arrested directly at the alleged scene then a file was highly likely to have been submitted this way to the CPS for final decision in any case.
The information you have provided is far too brief for any one here to really answer questions about this particular situation and I would advise you not to disclose further info on a public forum. However, from what you have disclosed i'd be surprised if the decision is to charge, but I could be very wrong.