Hi, and thanks for your medical question on eHealth forum!
If you were expecting your period around 20-22nd of January and missed them and you also have 11 negative pregnancy tests then in all probability you are not pregnant. Yes, you can take a blood pregnancy test to know if you are pregnant or not as this is more confirmatory.
However if the blood pregnancy test too comes negative, then you need to consult your gynecologist to rule out other causes of delayed periods such as hypothyroidism, anemia, PCOS, hormonal imbalance, stress, life style changes, weight gain, weight loss etc. A confirmed diagnosis cannot be given on net. Hope this helps. Take care!