Will Covid go away in 4-5 days? Or not?

On April 21st, all of a sudden I had severe chills, body pain, headache, fever of 101. Next day , fearing Covid I gave Rapid Test which came negative and submitted for RT-PCR but stressed Bangalore BBMP never gave my results. On 22nd itself I started Dolo650, citrigine, Vitamin C, Z, some pain killers etc per doctors advice. For next four days, monitoring SpO2 and was 93 (today it is 98). On 4th day fever started coming down and 5th day evening completely went away. Now, my question is, does Covid go away in just 4-5 days? How do I know if it was Covid or Something else? My SpO2 baseline is about 97-98. I am confused if I need to go for vaccination or not? What is the correct time to go for anti-gen test? Now I have completed 3 weeks after recovery. Can I order antigen test now and can I go for vaccination or not?