Using Minoxidil for 3 months. It didn't stop my hair loss. Shall I continue or leave it? Is it safe?

In my opinion, you should give minoxidil 3 to 6 months to determine if it is effective for you. The success  rate for minoxidil is approximately 40%. This has to do with the fact that not everybody has the enzyme to break minoxidil down to its active form. A microneedle roller may also add to its effectiveness.You should also consider using low level laser as well as platelet rich plasma. Find a hair loss expert who can help you with your treatment plan. Hope this helps.

Definitely continue if it is not presenting you with any adverse effects.   A good minoxidil should not be oily and should leave the hair manageable.   You will begin seeing results over the next 3 months. Most importantly, ensure that its use is continuous.  Minoxidil will actually cause more shedding if used intermittently. You can measure your progress by taking a picture with the same camera, same time of day, same lighting, from 3 different angles of your scalp.  You can then see how your hair has changed by looking at the pictures over time.  Also make sure to massage the minoxidil in.  Minoxidil works well on most patients.  Those whom get less than desirable results are either using an ineffective minoxidil preparation, not using in continuously, or not massaging the solution in. 

Minoxidil often takes a full year to see the benefits so you must be patient and stay on the treatment until the year has passed

Three months is usually not enough time to determine if minoxidil is working, so I would continue for at least another three months. The effect may not be noticeable unless you have been experiencing a lot of shedding ("hair fall"), in which case a decrease in shedding is a very good sign; otherwise, you may just notice that your hair loss isn't getting any worse. If if you haven't already seen a dermatologist or a hair transplant surgeon who could properly diagnose the cause of your hair loss, I would certainly recommend that. Assuming that you are a man and have ordinary male pattern balding, or androgenetic alopecia, the most important thing is for you to get started on finasteride and possibly low level laser therapy (LLLT).