Can Contraceptive Be Taken Even When There Is Delay In Periods?

Im 19 and about 5ft2, and weigh 8st. Since i was 16 i have been on various contraceptives however each one has resulted in constant bleeding. I have persisted for three years now and still have not found something that suits my body and have lost hope and even confidence in my doctor. I have had the usual investigations such as ultrasound, hysteroscopy and laperoscopy all of which were to no avail. I have now started to see an gynaecologist and have been perscribed 50mg of contraceptive pill to see if a higher dose will have an effect. I have been waiting to start this at the start of my period however i am now about 3 weeks late i have done a test and am not pregnant. However i am aware of a bloated abdoman and swelling on the right ovary area. Can you shed any light on my on going problem and my current dilema of my late period and shall i just start taking my pills anyway otherwise i could be waiting for ages and being in a long term relationship i dont feel condoms are that reliable?